GIFT   OF 

MICHAEL  REESE 


THE    NEW    ASTRONOMY 


THE    NEW    ASTRONOMY 


BY 


SAMUEL    PIERPONT    LANGLEY,    PH.D.,  LL.D, 

DIRECTOR  OF  THE  ALLEGHENY   OBSERVATORY,  MEMBER   NATIONAL  ACADEMY, 
FELLOW   ROYAL  ASTRONOMICAL   SOCIETY,  ETC.,   ETC. 


BOSTON. 
TICKNOR    AND     COMPANY 

211  Fremont  Street 

1888  - 


COPYRIGHT,  1884,  1885,  1886,  AND  1887,  BY  THE  CENTURY  Co.; 
AND  1887,  BY  S.  P.  LANGLEY. 

3  ^f- 3 

All  right/  reserved 


Jlnfbrrsitn  press: 
JOHN  WILSON  AND  SON,  CAMBRIDGE. 


PREFACE. 


T  HAVE  written  these  pages,  not  for  the  professional  reader, 
-*-  but  with  the  hope  of  reaching  a  part  of  that  educated 
public  on  whose  support  he  is  so  often  dependent  for  the 
means  of  extending  the  boundaries  of  knowledge. 

It  is  not  generally  understood  that  among  us  not  only  the 
support  of  the  Government,  but  with  scarcely  an  exception 
every  new  private  benefaction,  is  devoted  to  "  the  Old "  As- 
tronomy, which  is  relatively  munificently  endowed  already ; 
while  that  which  I  have  here  called  "the  New,"  so  fruitful  in 
results  of  interest  and  importance,  struggles  almost  unaided. 

We  are  all  glad  to  know  that  Urania,  who  was  in  the  begin- 
ning but  a  poor  Chaldean  shepherdess,  has  long  since  become 
well-to-do,  and  dwells  now  in  state.  It  is  far  less  known  than 
it  should  be  that  she  has  a  younger  sister  now  among  us, 
bearing  every  mark  of  her  celestial  birth,  but  all  unendowed 
and  portionless.  It  is  for  the  reader's  interest  in  the  latter 
that  this  book  is  a  plea. 


CONTENTS. 


CHAPTER  PAGE 

I.  SPOTS  ON  THE  SUN 1 

II.  THE  SUN'S  SURROUNDINGS 35 

III.  THE  SUN'S  ENERGY 70 

IV.  THE  SUN'S  ENERGY  (Continued) 91 

V.  THE  PLANETS  AND  THE  MOON 117 

VI.  METEORS 175 

VII.  COMETS 199 

VIII.  THE  STARS  .  221 


INDEX 253 


X  LIST   OF  ILLUSTRATIONS. 

FlGl'BE  pA,;K 

24.  SPOT  OF  MARCH  31,  1875 28 

25.  TYPICAL  ILLUSTRATION  OF  FAYE'S  THEORY 29 

26.  SPOT  OF  OCT.  13,  1876 30 

27.  PHOTOGRAPH  OF  EDGE  OF  SUN 31 

28.  FACULA 33 

29.  LUNAR  CONE  SHADOW 36 

30.  TRACK  OF  LUNAR  SHADOW 39 

31.  INNER  CORONA  ECLIPSE  OF  1869 40 

32.  SKETCH  OF  OUTER  CORONA,  1869 41 

33.  TACCHINI'S  DRAWING  OF  CORONA  OF  1870 43 

34.  WATSON'S  NAKED-EYE  DRAWING  OF  CORONA  OF  1870 44 

35.  PHOTOGRAPH  SHOWING  COMMENCEMENT  OF  OUTER  CORONA  ...  45 

36.  ECLIPSE  OF  1857,  DRAWING  BY  LIAIS 48 

37.  ENLARGEMENT  OF  PART  OF  FIG.  38 49 

38.  FAC-SIMILE  OF  PHOTOGRAPH  OF  CORONA  OF  1871 51 

39.  "SPECTRES" 54 

40.  OUTER  CORONA  OF  1878 57 

41.  SPECTROSCOPE  SLIT  AND  SOLAR  IMAGE 59 

42.  SLIT  AND  PROMINENCES 59 

43.  TACCHINI'S  CHROMOSPHERIC  CLOUDS 62 

44.  TACCHINI'S  CHROMOSPHERIC  CLOUDS 62 

45.  VOGEL'S  CHROMOSPHERIC  FORMS 64 

46.  TACCHINI'S  CHROMOSPHERIC  FORMS 66 

47.  ERUPTIVE  PROMINENCES 67 

48.  SUN-SPOTS  AND  PRICE  OF  GRAIN 77 

49.  SUN-SPOT  OF  Nov.  16,  1882,  AND  EARTH 80 

50.  GREENWICH    RECORD    OF    DISTURBANCE    OF    MAGNETIC    NEEDLE, 

Nov.  16  AND  17,  1882 81 

51.  SUN-SPOTS  AND  MAGNETIC  VARIATIONS 87 

.~L'.    <  ii: i.i  \\VICH  MAGNETIC  OBSERVATIONS,  AUG.  3  AND  5,  1872      .     .  89 

53.   ONE  CUBIC  CENTIMETRE 93 

."»!.    POUILLET'S  PYRHELIOMETER 93 

55.   BERXIERES'S  GREAT  BURNING-GLASS          ....  103 


LIST   OF  ILLUSTRATIONS.  xi 

FIGURE  PAGE 

56.  A  "  POUR  "  FROM  THE  BESSEMER  CONVERTER 105 

57.  PHOTOMETER-BOX 108 

58.  MOUCHOT'S  SOLAR  ENGINE 109 

59.  ERICSSON'S  NEW  SOLAR  ENGINE,  NOW  IN  PRACTICAL  USE  IN  NEW 

YORK 113 

GO.    SATURN 119 

61.  THE  EQUATORIAL  TELESCOPE  AT  WASHINGTON 122 

62.  JUPITER,  MOON,  AND  SHADOW 125 

63.  THREE  VIEWS  OF  MARS 129 

64.  MAP  OF  MARS 129 

65.  THE  MOON 137 

66.  THE  FULL  MOON 141 

67.  GLASS  GLOBE,  CRACKED 145 

68.  PLATO  AND  THE  LUNAR  ALPS 149 

69.  THE  LUNAR  APENNINES  :  ARCHIMEDES 153 

70.  VESUVIUS  AND  NEIGHBORHOOD  OF  NAPLES  .     .     .     .     .     .     .     .     .  157 

71.  PTOLEMY  AND  ARZACHEL 161 

72.  MERCATOR  AND  CAMPANUS 165 

73.  WITHERED  HAND .  168 

74.  IDEAL  LUNAR  LANDSCAPE  AND  EARTH-SHINE 169 

75.  WITHERED  APPLE 171 

76.  GASSENDI.     Nov.  7,  1867   . 173 

77.  THE  CAMP  AT  MOUNT  WHITNEY 177 

78.  VESUVIUS  DURING  AN  ERUPTION 183 

79.  METEORS  OBSERVED  Nov.   13  AND  14,  1868,  BETWEEN  MIDNIGHT 

AND  FIVE  O'CLOCK,  A.  M. 189 

80.  COMET  OF  DONATI,  SEPT.  16,  1858 201 

81.  "A  PART  OF  A  COMET" 203 

82.  COMET  OF  DONATI,  SEPT.  24,  1858 205 

83.  COMET  OF  DONATI,  OCT.  3,  1858 209 

84.  COMET  OF  DONATI,  OCT.  9,  1858 213 

85.  COMET  OF  DONATI,  OCT.  5,  1858 217 

86.  TYPES  OF  STELLAR  SPECTRA  .  222 


xii  LIST   OF  ILLUSTRATIONS. 

FIGURE  PAGE 

87.  THE  MILKY  WAY 225 

88.  SPECTRA  OF  STARS  IN  PLEIADES 231 

89.  SPECTRUM  OF  ALDEBARAN 235 

90.  SPECTRUM  OF  VEGA 235 

91.  GREAT  NEBULA  IN  ORION 239 

92.  A  FALLING  MAN 243 

93.  A  FLASH  OF  LIGHTNING 245 


THE    NEW   ASTRONOMY. 


i. 

SPOTS   ON  THE   SUN. 

visitor  to  Salisbury  Plain  sees  around  him  a  lonely 
waste,  utterly  barren  except  for  a  few  recently  planted 
trees,  and  otherwise  as  desolate  as  it  could  have  been  when 
Hengist  and  Horsa  landed  in  Britain ;  for  its  monotony  is  still 
unbroken  except  by  the  funeral  mounds  of  ancient  chiefs,  which 
dot  it  to  its  horizon,  and  contrast  strangely  with  the  crowded  life 
and  fertile  soil  which  everywhere  surround  its  borders.  In  the 
midst  of  this  loneliness  rise  the  rude,  enormous  monoliths  of 
Stonehenge,  —  circles  of  gray  stones,  which  seem  as  old  as  time, 
and  were  there,  as  we  now  are  told,  the  temple  of  a  people  which 
had  already  passed  away,  and  whose  worship  was  forgotten, 
when  our  Saxon  forefathers  first  saw  the  place. 

In  the  centre  of  the  inner  circle  is  a  stone  which  is  believed 
once  to  have  been  the  altar ;  while  beyond  the  outmost  ring, 
quite  away  to  the  northeast  upon  the  open  plain,  still  stands  a 
solitary  stone,  set  up  there  evidently  with  some  special  object 
by  the  same  unknown  builders.  Seen  under  ordinary  circum- 
stances, it  is  difficult  to  divine  its  connection  with  the  others ; 
but  we  are  told  that  once  in  each  year,  upon  the  morning  of  the 
longest  day,  the  level  shadow  of  this  distant,  isolated  stone  is 
projected  at  sunrise  to  the  very  centre  of  the  ancient  sanctuary, 
and  falls  just  upon  the  altar.  The  primitive  man  who  devised 

1 


2  THE  NEW  ASTRONOMY. 

this  was  both  astronomer  and  priest,  for  he  not  only  adored  the 
risen  god  whose  first  beams  brought  him  light  and  warmth,  but 
he  could  mark  its  place,  and  though  utterly  ignorant  of  its  na- 
ture, had  evidently  learned  enough  of  its  motions  to  embody 
his  simple  astronomical  knowledge  in  a  record  so  exact  and  so 
enduring  that  though  his  very  memory  has  gone,  common  men 
are  still  interested  in  it;  for,  as  I  learned  when  viewing  the 
scene,  people  are  accustomed  to  come  from  all  the  surrounding 
country,  and  pass  in  this  desolate  spot  the  short  night  preceding 
the  longest  day  of  the  year,  to  see  the  shadow  touch  the  altar 
at  the  moment  of  sunrise. 

Most  great  national  observatories,  like  Greenwich  or  Wash- 
ington, are  the  perfected  development  of  that  kind  of  astronomy 
of  which  the  builders  of  Stonehenge  represent  the  infancy. 
Those  primitive  men  could  know  where  the  sun  would  rise  on 
a  certain  day,  and  make  their  observation  of  its  place,  as  we  see, 
very  well,  without  knowing  anything  of  its  physical  nature.  At 
Greenwich  the  moon  has  been  observed  with  scarcely  an  inter- 
mission for  one  hundred  and  fifty  years,  but  we  should  mistake 
greatly  did  we  suppose  that  it  was  for  the  purpose  of  seeing 
what  it  was  made  of,  or  of  making  discoveries  in  it.  This  im- 
mense mass  of  Greenwich  observations  is  for  quite  another  pur- 
pose,—  for  the  very  practical  purpose  of  forming  the  lunar 
tables,  which,  by  means  of  the  moon's  place  among  the  stars, 
will  tell  the  navigator  in  distant  oceans  where  he  is,  and  conduct 
the  fleets  of  England  safely  home. 

In  the  observatory  at  Washington  one  may  see  a  wonderfully 
exact  instrument,  in  which  circles  of  brass  have  replaced  circles 
of  stone,  all  so  bolted  between  massive  piers  that  the  sun  can  be 
observed  by  it  but  once  daily,  as  it  crosses  the  meridian.  Tliis 
instrument  is  the  completed  attainment  along  that  long  line  of 
progress  in  one  direction,  of  which  the  solitary  stone  at  Stone- 
henge marks  the  initial  step,  —  the  attainment,  that  is,  purely  of 


SPOTS    ON  THE  SUN.  3 

precision  of  measurement ;  for  the  astronomer  of  to-day  can  still 
use  his  circles  for  the  special  purpose  of  fixing  the  sun's  place 
in  the  heavens,  without  any  more  knowledge  of  that  body's 
chemical  constitution  than  had  the  man  who  built  Stonehenge. 

Yet  the  object  of  both  is,  in  fact,  the  same.  It  is  true  that 
the  functions  of  astronomer  and  priest  have  become  divided  in 
the  advance  of  our  modern  civilization,  which  has  committed  the 
special  cultivation  of  the  religious  aspect  of  these  problems  to 
a  distinct  profession  ;  while  the  modern  observer  has  possibly 
exchanged  the  emotions  of  awe  and  wonder  for  a  more  exact 
knowledge  of  the  equinox  than  was  possessed  by  his  primitive 
brother,  who  both  observed  and  adored.  Still,  both  aim  at  the 
common  end,  not  of  learning  what  the  sun  is  made  of,  but  of 
AY  here  it  will  be  at  a  certain  moment;  for  the  prime  object  of 
astronomy,  until  very  lately  indeed,  has  still  been  to  say  where 
any  heavenly  body  is,  and  not  what  it  is.  It  is  this  precision 
of  measurement,  then,  which  has  always  —  and  justly  —  been 
a  paramount  object  of  this  oldest  of  the  sciences,  not  only  as  a 
good  in  itself,  but  as  leading  to  great  ends ;  and  it  is  this  which 
the  poet  of  Urania  has  chosen  rightly  to  note  as  its  characteristic, 
when  he  says,  — 

u  That  little  Vernier,  on  whose  slender  lines 
The  midnight  taper  trembles  as  it  shines, 
Tells  through  the  mist  where  dazzled  Mercury  burns, 
And  marks  the  point  where  Uranus  returns." 

But  within  a  comparatively  few  years  a  new  branch  of 
astronomy  has  arisen,  which  studies  sun,  moon,  and  stars  for 
what  they  are  in  themselves,  and  in  relation  to  ourselves.  Its 
study  of  the  sun,  beginning  with  its  external  features  (and  full  of 
novelty  and  interest,  even,  as  regards  those),  led  to  the  further 
inquiry  as  to  what  it  was  made  of,  and  then  to  finding  the  un- 
expected relations  which  it  bore  to  the  earth  and  our  own  daily 
lives  on  it,  the  conclusion  being  that,  in  a  physical  sense,  it  made 


4  THE  NEW  ASTRONOMY. 

us  and  re-creates  us,  as  it  were,  daily,  and  that  the  knowledge  of 
the  intimate  ties  which  unite  man  with  it  brings  results  of  the 
most  practical  and  important  kind,  which  a  generation  ago  were 
unguessed  at. 

This  new  branch  of  inquiry  is  sometimes  called  Celestial 
Physics,  sometimes  Solar  Physics,  and  is  sometimes  more 
rarely  referred  to  as  the  New  Astronomy.  I  will  call  it  here 
by  this  title,  and  try  to  tell  the  reader  something  about  it  which 
may  interest  him,  beginning  with  the  sun. 


FIG.    1.  —  THE    SUN'S    SURROUNDINGS. 

The  whole  of  what  we  have  to  say  about  the  sun  and  stars 
presupposes  a  knowledge  of  their  size  and  distance,  and  we  may 
take  it  for  granted  that  the  reader  has  at  some  time  or  another 
heard  such  statements  as  that  the  moon's  distance  is  two  hun- 
dred and  forty  thousand  miles,  and  the  sun's  ninety-three  million 
(and  very  probably  has  forgotten  them  again  as  of  no  practical 
concern).  He  will  not  be  offered  here  the  kind  of  statistics 
which  he  would  expect  in  a  college  text-book;  but  we  must 
linger  a  moment  on  the  threshold  of  our  subject  —  the  nature 
of  these  bodies  —  to  insist  on  the  real  meaning  of  such  figures 
ns  those  just  quoted.  We  are  accustomed  to  look  on  the  sun 


SPOTS   ON   THE  SUN.  5 

and  moon  as  far  off  together  in  the  sky ;  and  though  we  know 
the  sun  is  greater,  we  are  apt  to  think  of  them  vaguely  as  things 
of  a  common  order  of  largeness,  away  among  the  stars.  It 
would  be  safe  to  say  that  though  nine  out  of  ten  readers  have 
learned  that  the  sun  is  larger  than  the  moon,  and,  in  fact,  larger 
than  the  earth  itself,  most  of  them  do  not  at  all  realize  that  the 
difference  is  so  enormous  that  if  we  could  hollow  out  the  sun's 
globe  and  place  the  earth  in  the  centre,  there  would  still  be  so 
much  room  that  the  moon  might  go  on  moving  in  her  present 
orbit  at  two  hundred  and  forty  thousand  miles  from  the  earth,  — 
all  within  the  globe  of  the  sun  itself,  —  and  have  plenty  of  room 
to  spare. 

As  to  the  distance  of  ninety-three  million  miles,  a  cannon-ball 
would  travel  it  in  about  fifteen  years.  It  may  help  us  to  remem- 
ber that  at  the  speed  attained  by  the  Limited  Express  on  our 
railroads  a  train  which  had  left  the  sun  for  the  earth  when  the 
''Mayflower"  sailed  from  Delftshaveii  with  the  Pilgrim  Fathers, 
and  which  ran  at  that  rate  day  and  night,  would  in  1887  still  be 
a  journey  of  some  years  away  from  its  terrestrial  station.  The 
fare  at  the  customary  rates,  it  may  be  remarked,  would  be 
rather  over  two  million  five  hundred  thousand  dollars,  so  that 
it  is  clear  that  we  should  need  both  money  and  leisure  for  the 
journey. 

Perhaps  the  most  striking  illustration  of  the  sun's  distance  is 
given  by  expressing  it  in  terms  of  what  the  physiologists  would 
call  velocity  of  nerve  transmission.  It  has  been  found  that  sen- 
sation is  not  absolutely  instantaneous,  but  that  it  occupies  a  very 
minute  time  in  travelling  along  the  nerves ;  so  that  if  a  child 
puts  its  finger  into  the  candle,  there  is  a  certain  almost  incon- 
ceivably small  space  of  time,  say  the  one-hundredth  of  a  second, 
before  he  feels  the  heat.  In  case,  then,  a  child's  arm  were  long 
enough  to  touch  the  sun,  it  can  be  calculated  from  this  known 
rate  of  transmission  that  the  infant  would  have  to  live  to  be  a 


6  THE  NEW  ASTRONOMY. 

man  of  over  a  hundred  before  it  knew  that  its  fingers  were 
burned. 

Trying  with  the  help  of  these  still  inadequate  images,  we 
may  get  some  idea  of  the  real  size  and  distance  of  the  sun.  I 
could  wish  not  to  have  to  dwell  upon  such  figures,  that  seem, 
however,  indispensable ;  but  we  are  now  done  with  these,  and 


FIG.  1\  —  VIEW  OF  THE  SUN  ON  SEPT.  20,  1870.  FIG.  .'5.  —  THE  SUN  ON  SEPT.  22,  1870. 

(FROM  A  PHOTOGRAPH  ) 

are  ready  to  turn  to  the  telescope  and  see  what  the  sun  itself 
looks  like. 

The  sun,  as  we  shall  learn  later,  is  a  star,  and  not  a  particu- 
larly large  star.  It  is,  as  has  been  said,  "only  a  private  in  the 
host  of  heaven,"  but  it  is  one  of  that  host;  it  is  one  of  those 
glittering  points  to  which  we  have  been  brought  near.  Let  us 
keep  in  mind,  then,  from  the  first,  what  we  shall  see  confirmed 
later,  that  there  is  an  essentially  similar  constitution  in  them  all, 
and  not  forget  that  when  we  study  the  sun,  as  we  now  begin  to 
do,  we  arc  >tudying  the  stars  also. 

If  we  were  called  on  to  give  a  description  of  the  earth  and  all 
that  is  on  it,  it  would  be  easily  understood  that  the  task  was 
impossibly  great,  and  that  even  an  account  of  its  most  striking 
general  features  might  fill  volumes.  So  it  is  with  the  sun  ;  and 


SPOTS   ON  THE  SUN.  7 

we  shall  find  that  in  the  description  of  the  general  character  of 
its  immediate  surface  alone,  there  is  a  great  deal  to  be  told. 
First,  let  us  look  at  a  little  conventional  representation  (Fig.  1), 
as  at  a  kind  of  outline  of  the  unknown  regions  we  are  about  to 
explore.  The  circle  represents  the  Photosphere,  which  is  simply 
what  the  word  implies,  that  " sphere"  of  " light"  which  we  have 
daily  before  our  eyes,  or  which  we  can  study  with  the  telescope. 
Outside  this  there  is  a  thin  envelope,  which  rises  here  and  there 
into  irregular  prominences,  some  orange-scarlet,  some  rose-pink. 
This  is  the  Chromosphere,  a  thin  shell,  mainly  of  crimson  and 
scarlet  tints,  invisible  even  to 
the  telescope  except  at  the  time 
of  a  total  eclipse,  when  alone 
its  true  colors  are  discernible, 
but  seen  as  to  its  form  at  all 
times  by  the  spectroscope.  It 
is  always  there,  not  hidden  in 
any  wayr  .and  yet  not  seen, 
only  because  it  is  overpowered 
by  the  intenser  brilliancy  of  the 
Photosphere,  as  a  glowworm's 

FIG.  4.  —  THE   SUN   ON   SEPT.  20,  1870. 

shine  would  be  it  it  were  put 

beside  an  electric  light.  Outside  all  is  the  strange  shape,  which 
represents  the  mysterious  Corona,  seen  by  the  naked  eye  in  a 
total  eclipse,  but  at  all  other  times  invisible  even  to  telescope 
and  spectroscope,  and  of  whose  true  nature  we  are  nearly  igno- 
rant from  lack  of  opportunity  to  study  it. 

Disregarding  other  details,  let  us  carry  in  our  minds  the  three 
main  divisions,  —  the  Photosphere,  or  daily  visible  surface  of 
the  sun,  which  contains  nearly  all  its  mass  or  substance ;  the 
Chromosphere;  and  the  unsubstantial  Corona,  which  is  never- 
theless larger  than  all  the  rest.  We  begin  our  examination 
with  the  Photosphere. 


8 


THE  NEW  ASTRONOMY. 


There  are  records  of  spots  having  been  seen  with  the  naked 
eye  before  the  invention  of  the  telescope,  but  they  were  sup- 
posed to  be  planets  passing  between  us  and  the  surface ;  and  the 
idea  that  the  sun  was  pure  fire,  necessarily  immaculate,  was 
taught  by  the  professors  of  the  Aristotelian  philosophy  in  mediae- 
val schools,  and  regarded  almost  as  an  article  of  religious  faith. 
We  can  hardly  conceive,  now,  the  shock  of  the  first  announce- 
ment that  spots  were  to  be  found  on  the  sun,  but  the  notion 
partook  in  contemporary  minds  at  once  of  the  absurd  and  the 


FIG.  5.  —  SEPT.  19,  1870.  FIG.  0.  —  SEPT.  20,  1870. 

(ENGRAVED  FROM  A  PHOTOGRAPH  BY  RUTHERFURD.) 

impious:  and  we  notice  here,  what  we  shall  have  occasion  to 
notice  again,  that  these  physical  discoveries  from  the  first  affect 
men's  thoughts  in  unexpected  ways,  and  modify  their  scheme 
of  the  moral  universe  as  well  as  of  the  physical  one. 

Very  little  indeed  was  added  to  the  early  observations  of 
Fabricius  and  Galileo  until  a  time  within  the  remembrance  of 
many  of  us ;  for  it  is  since  the  advent  of  the  generation  now  on 
the  stage  that  nine-tenths  of  the  knowledge  of  the  subject  has 
been  reached. 

Let  us  first  take  a  general  view  of  the  sun,  and  afterward 
study  it  in  detail.  What  we  see  with  a  good  telescope  in  this 
general  view  is  something  like  this.  Opposite  are  three  succes- 


SPOTS   ON  THE  SUN. 


give  views  (Figs.  2,  3,  4)  taken  on  three  successive  days,  —  quite 
authentic  portraits,  since  the  sun  himself  made  them  ;  they  beinir. 
in  fact,  projected  telescopic  images  which  have  been  fixed  for  us 
by  photography,  and  then  exactly  reproduced  by  the/  engraver. 
The  first  was  taken  (by  Mr.  Rutherfurd,  of  New  York)  on  the 


FIG.  7. —  SEPT.  21,  1S70. 


FIG.  8.  —  SEPT.  22.  1870. 


20th  of  September,  1870,  when  a  remarkably  large  spot  had 
come  into  view.  It  is  seen  here  not  far  from  the  eastern  edge 
(the  left  hand  in  the  engraving),  and  numerous  other  spots  are 
also  visible.  The  reader  should  notice  the  position  of  these, 
and  then  on  turning  to  the  next  view  (Fig.  3,  taken  on  Septem- 
ber 22d)  he  will  see  that  they  have  all  shifted  their  places,  by  a 
common  motion  toward  the  west.  The  great  spot  on  the  left 
has  now  got  well  into  view,  and  we  can  see  its  separate  parts ; 
the  group  which  was  on  the  left  of  the  centre  has  got  a  little  to 
the  right  of  it,  and  so  on.  From  the  common  motion  of  them 
all,  we  might  suspect  that  the  sun  was  turning  round  on  an  axis 
like  the  earth,  carrying  the  spots  with  it :  and  as  we  continue  to 
observe,  this  suspicion  becomes  certainty.  In  the  third  view 
(Fig.  4),  taken  on  September  26th,  the  spot  we  first  saw  on  the 
left  has  travelled  more  than  half  across  the  disk,  while  others  we 
saw  on  September  20th  have  approached  to  the  right-hand  edge 
or  passed  wholly  out  of  sight  behind  it.  The  sun  does  rotate, 


10  THE  NEW  ASTRONOMY. 

then,  but  in  twenty -five  or  twenty-six  of  our  days,  —  I  say 
twenty-five  or  twenty-six,  because  (what  is  very  extraordinary) 
it  does  not  turn  all-of-a-piece  like  the  earth,  but  some  parts 
revolve  faster  than  others,  —  not  only  faster  in  feet  and  inches, 
but  in  the  number  of  turns, — just  as  though  the  rim  of  a  car- 
riage wheel  were  to  make  more  revolutions  in  a  mile  than  the 
spokes,  and  the  spokes  more  than  the  hub.  Of  course  no  solid 
wheel  could  so  turn  without  wrenching  itself  in  pieces,  but  that 
the  great  solar  wheel  does,  is  incontestable ;  and  this  alone  is  a 
convincing  proof  that  the  sun's  surface  is  not  solid,  but  liquid  or 
gaseous. 

But  let  us  return  to  the  great  spot  which  we  saw  coming 
round  the  eastern  edge.  Possibly  the  word  " great"  may  seem 
misapplied  to  what  was  but  the  size  of  a  pin-head  in  the  first 
engraving,  but  we  must  remember  that  the  disk  of  the  sun 
there  shown  is  in  reality  over  800,000  miles  in  diameter.  We 


FIG.  !'.  —  SEPT.  23,  1870.  FIG.  10.  —  SEPT.  20,  1870. 

shall  soon  see  whether  this  spot  deserves  to  be  called  "  great " 
or  not. 

Next  we  have  six  enlarged  views  of  it  on  the  19th,  20th,  21st, 
22d,  23d,  and  26th.  On  the  19th  it  is  seen  very  near  the  eastern 
limb,  showing  like  a  great  hole  in  the  sun,  and  foreshortened  as 
it  comes  into  view  around  the  dark  edge ;  for  the  edge  of  the 


SPOTS   ON  THE  SUN. 


11 


sun.  is  really  darker  than  the  central  parts,  as  it  is  shown  here, 
or  as  one  may  see  even  through  a  smoked  glass  by  careful 
attention.  On  the  20th  we  have  the  edge  still  visible,  but  on 
the  21st  the  spot  lias  advanced  so  far  that  the  edge  cannot  be 
shown  for  want  of  room.  We  see  distinctly  the  division  of  the 
spot  into  the  outer  shades  which  constitute  the  penumbra,  and 


•>..•••&,•>  :-;,;,•• 


|,---*-;*        c^rS>':-  *  '  /  'r     ^  ' 

.«       x    *"  x        -      *  "V  %   ^      ^  i  l^      •>     » 

I*  "^T"-'^  •  ;:;  '^  /  4  ^          "'*     ^ 

^4  *        4*       \^  '-*.       J      ^          '"  "'^         "^  "         ^  fc^"^  "^  *•' 


FIG.  11.  —  NASMYTH'S  WILLOW  LEAVES.     (FROM  HERSCHEL'S  "OUTLINES  OF  ASTRONOMY.") 

the  inner  darker  ones  which  form  the  umbra  and  nucleus.  We 
notice  particularly  in  this  enlarged  view,  by  comparing  the 
appearances  on  the  21st,  22d,  and  23d,  that  the  spot  not  only 
turns  with  the  sun  (as  we  have  already  learned),  but  moves  and 
changes  within  itself  in  the  most  surprising  way,  like  a  terrestrial 
cloud,  which  not  only  revolves  with  the  rest  of  the  globe,  but 
varies  its  shape  from  hour  to  hour.  This  is  seen  still  more 
plainly  when  we  compare  the  appearance  on  the  23d  with  that 
on  the  26th,  only  three  days  later,  where  the  process  has  begun 
by  which  the  spot  finally  breaks  up  and  forever  disappears.  On 


12 


THE  NEW  ASTRONOMY. 


looking  at  all  this,  the  tremendous  scale  on  which  the  action 
occurs  must  be  borne  in  mind.  On  the  21st,  for  instance,  the 
umbra,  or  dark  central  hole,  alone  was  large  enough  to  let 
the  whole  globe  of  our  own  earth  drop  in  without  touching  the 
sides  !  We  shall  have  occasion  to  recur  to  this  view  of  the  21st 
September  again. 

In  looking  at  this  spot  and  its  striking  changes,  the  reader 
must  not  omit  to  notice,  also,  a  much  less  obvious  feature,  —  the 
vaguely  seen  mottlings  which  show  all  over  the  sun's  surface, 
both  quite  away  from  the  spots  and  also  close  to  them,  and 
which  seem  to  merge  into  them. 

I  think  if  we  assign  one  year  rather 
than  another  for  the  birth  of  the  youth- 
ful science  of  solar  physics,  it  should  be 
1861,  when  Kirchhoff  and  Bunsen  pub- 
lished their  memorable  research  on 
Spectrum  Analysis,  and  when  Nasmyth 
observed  what  he  called  the  "  willow- 
leaf"  structure  of  the  solar  surface  (see 
Fig.  11).  Mr.  Nasmyth,  with  a  very  pow- 
erful reflecting  telescope,  thought  he  had 
succeeded  in  finding  what  these  faint 
mottlings  really  are  composed  of,  and 
believed  that  he  had  discovered  in  them 
some  most  extraordinary  things.  This  is 

what  he  thought  he  saw:  The  whole  sun  is,  according  to  him, 
covered  with  huge  bodies  of  most  definite  shape,  that  of  the 
oblong  willow  leaf,  and  of  enormous  but  uniform  size;  and 
the  faint  mottlings  the  reader  has  just  noticed  are,  according  to 
him,  made  up  of  these.  "  These,"  he  says,  "  cover  the  whole 
disk  of  the  sun  (except  in  the  space  occupied  by  the  spots)  in 
countless  millions,  and  lie  crossing  each  other  in  every  imagi- 
nable direction."  Sir  John  Herschel  took  a  particular  interest 


FIG.  12.  —  THE  CACTUS  TYPE. 

(FROM  SECCHI'S  "LE  SOLEIL.") 


SPOTX    OX    Til  hi   SI  \. 


in  the  supposed  discovery,  and,  treating  it  as  a  matter  of 
established  fact,  proceeded  to  make  one  of  the  most  amazing 
suggestions  in  explanation  that  ever  came  from  a  scientific 
man  of  deserved  eminence.  We  must  remember  how  much 
there  is  unknown  in  the  sun  still,  and  what  a  great  mystery 
even  yet  overhangs  many  of  our  relations  to  that  body  which 
maintains  our  own  vital 
action,  when  we  read  the 
following  words,  which  are 
Herschel's  own.  Speaking 
of  these  supposed  spindle- 
shaped  monsters,  he  says: 

"The  exceedingly  definite 
shape  of  these  objects,  their 
exact  similarity  to  one  another, 
and  the  way  in  which  they  lie 
across  and  athwart  each  other, 
—  all  these  characters  seem 
quite  repugnant  to  the  notion 
of  their  being  of  a  vaporous,  a 
cloudy,  or  a  fluid  nature.  Noth- 
ing remains  but  to  consider 
them  as  separate  and  indepen- 
dent sheets,  flakes,  or  scales, 
having  some  sort  of  solidity. 

And  these  .  .  .  are  evidently  the  immediate  sources  of  the  solar  light  and 
heat,  by  whatever  mechanism  or  whatever  processes  they  may  be  enabled 
to  develop,  and  as  it  were  elaborate,  these  elements  from  the  bosom  of  the 
non-luminous  fluid  in  which  they  appear  to  float.  Looked  at  in  this  point 
of  view,  we  cannot  refuse  to  regard  them  as  organisms  of  some  peculiar 
and  amazing  kind ;  and  though  it  would  be  too  daring  to  speak  of  such 
organization  as  partaking  of  the  nature  of  life,  yet  we  do  know  that  vital 
action  is  competent  to  develop  at  once  heat  and  light  and  electricity." 

Such  are  his  words ;  and  when  we  consider  that  each  of  these 
solar  inhabitants  was  supposed  to  extend  about  two  hundred  by 


FIG.   13. EQUATORIAL   TELESCOPE   AND 

PROJECTION. 


14  THE  NEW  ASTRONOMY. 

one  thousand  miles  upon  the  surface  of  the  fiery  ocean,  we  may 
subscribe  to  Mr.  Proctor's  comment,  that  "  Milton's  picture  of 
him  who  on  the  fires  of  hell  t  lay  floating  many  a  rood,'  seems 
tame  and  commonplace  compared  with  Herschel's  conception  of 
these  floating  monsters,  the  least  covering  a  greater  space  than 
the  British  Islands." 

I  hope  I  may  not  appear  wanting  in  respect  for  Sir  John 
Herschel  —  a  man  whose  memory  I  reverence  —  in  thus  citing 
views  which,  if  his  honored  life  could  have  been  prolonged,  he 

would  have  abandoned.  I 
do  so  because  nothing  else 
can  so  forcibly  illustrate 
the  field  for  wonder  and 
wild  conjecture  solar  phys- 
ics presented  even  a  few 
years  ago ;  and  its  sup- 
posed connection  with  that 

FIG.  14.  —  POLARIZING   EYE-PIECE. 

"  Vital  Force,"  which  was 

till  so  lately  accepted  by  physiology,  serves  as  a  kind  of  land- 
mark on  the  way  we  have  come. 

This  new  science  of  ours,  then,  youthful  as  it  is,  has  already 
had  its  age  of  fable. 

After  a  time  Nasmyth's  observation  was  attributed  to  imper- 
fect definition,  but  was  not  fairly  disproved.  He  had,  indeed,  a 
basis  of  fact  for  his  statement,  and  to  him  belongs  the  credit  of 
first  pointing  out  the  existence  of  this  minute  structure,  though 
he  mistook  its  true  character.  It  will  be  seen  later  how  the  real 
forms  might  be  mistaken  for  leaves,  and  in  certain  particular 
cases  they  certainly  do  take  on  a  very  leaf-like  appearance. 
Here  is  a  drawing  (Fig.  12)  which  Father  Secchi  gives  of  some 
of  them  in  the  spot  of  April  14,  1867,  and  which  he  compares 
to  a  branch  of  cactus.  He  remarks  somewhere  else  that  they 
resemble  a  crystallization  of  sal-ammoniac,  and  calls  them  veils 


FIG.  15.—  SPOT  OF  SEPT.  21,  1870.      (REDUCED  FROM  AN  ORIGINAL  DRAWING  BY  S.  P.  LANGLEY.) 


FIG.    16.  —  Sl'OT  OF  JIAUC1I   '.,  1873.       (HKI>tVKI>  FltoM  AN  olillilNAL  DRAWING  B 


SPOTS   ON  THE  SUN.  17 

of  most  intricate  structure.  This  was  the  state  of  our  knowledge 
in  1870,  and  it  may  seem  surprising  that  such  wonderful  state- 
ments had  not  been  proved  or  disproved,  when  they  referred 
to  mere  matters  of  observation.  But  direct  observation  is  here 
very  difficult  on  account  of  the  incessant  tremor  and  vibration 
of  our  own  atmosphere. 

The  surface  of  the  sun  may  be  compared  to  an  elaborate 
engraving,  filled  with  the  closest  and  most  delicate  lines  and 
hatchings,  but  an  engraving  which  during  ninety-nine  hun- 
dredths  of  the  time  can  only  be  seen  across  such  a  quivering 
mass  of  heated  air  as  makes  everything  confused  and  liable  to 
be  mistaken,  causing  what  is  definite  to  look  like  a  vaguely  seen 
mottling.  It  is  literally  true  that  the  more  delicate  features  we 
are  about  to  show,  are  only  distinctly  visible  even  by  the  best 
telescope  during  less  than  one-hundredth  of  the  time,  coming 
out  as  they  do  in  brief  instants  when  our  dancing  air  is  momen- 
tarily still,  so  that  one  who  has  sat  at  a  powerful  telescope  all 
day  is  exceptionally  lucky  if  he  has  secured  enough  glimpses 
of  the  true  structure  to  aggregate  five  minutes  of  clear  seeing, 
while  at  all  other  times  the  attempt  to  magnify  only  produces 
a  blurring  of  the  image.  This  study,  then,  demands  not  only 
fine  telescopes  and  special  optical  aids,  but  endless  patience. 

My  attention  was  first  particularly  directed  to  the  subject  in 
1870  (shortly  after  the  regular  study  of  the  Photosphere  was 
begun  at  the  Allegheny  Observatory  by  means  of  its  equa- 
torial telescope  of  thirteen  inches'  aperture),  with  the  view  of 
finding  out  what  this  vaguely  seen  structure  really  is.  Nearly 
three  years  of  constant  watching  were  given  to  obtain  the  results 
which  follow.  The  method  I  have  used  for  it  is  indicated  in  the 
drawing  (Fig.  13),  which  shows  the  preliminary  step  of  project- 
ing the  image  of  the  sun  directly  upon  a  sheet  of  paper,  divided 
into  squares  and  attached  to  the  eye-end  of  a  great  equatorial 
telescope.  When  this  is  directed  to  the  sun  in  a  darkened  dome, 


18 


THE  NEW  ASTRONOMY. 


the  solar  picture  is  formed  upon  the  paper  as  in  a  camera 
obscura,  and  this  picture  can  be  made  as  large  or  as  small  as 
we  please  by  varying  the  lenses  which  project  it.  As  the  sun 
moves  along  in  the  sky,  its  image  moves  across  the  paper ;  and 
as  we  can  observe  how  long  the  whole  sun  (whose  diameter  in 
miles  is  known)  takes  to  cross,  we  can-  find  how  many  miles 

correspond  to  the  time  it 
is  in  crossing  one  of  the 
squares,  and  so  get  the 
scale  of  the  future  draw- 
ing, and  the  true  size  in 
miles  of  the  spot  we  are 
about  to  study.  Then  a 
piece  of  clock-work  at- 
tached to  the  telescope  is 
put  in  motion,  and  it  be- 
gins to  follow  the  sun 
in  the  sky,  and  the  spot 
appears  fixed  on  the  pa- 
per. A  tracing  of  the 
spot's  outline  is  next 

made,  but  the  finer  details  are  not  to  be  observed  by  this 
method,  which  is  purely  preliminary,  and  only  for  the  purpose 
of  fixing  the  scale  and  the  points  of  the  compass  (so  to  speak)  on 
the  sun's  face.  The  projecting  apparatus  is  next  removed  arid 
replaced  by  the  polarizing  eye-piece.  Sir  William  Herschel 
used  to  avoid  the  blinding  effects  of  the  concentrated  solar  light 
by  passing  the  rays  through  ink  and  water,  but  the  phenomena 
of  "polarization"  have  been  used  to  better  advantage  in  modern 
apparatus.  This  instrument,  one  of  the  first  of  its  kind  ever 
constructed,  and  in  which  the  light  is  polarized  with  three  suc- 
cessive reflections  through  the  three  tubes  seen  in  the  drawing 
(Fig.  14),  was  made  in  Pittsburgh  as  a  part  of  the  gift  of  appa- 


FIO.  17.  —  SUN  ON  MARCH  5,  1873.       (FROM  A  DRAWING 
BY  8.  P.  LAXGLEY.) 


SPOTS   ON  THE  SUN.  19 

ratus  by  one  of  its  citizens  to  the  Observatory,  and  has  been 
most  useful.  By  its  aid  the  eye  can  be  safely  placed  where  the 
concentrated  heat  would  otherwise  melt  iron.  In  practice  I 
have  often  gazed  through  it  at  the  sun's^face  without  inter- 
mission from  four  to  five  hours,  with  no  more  fatigue  or  harm  to 
the  eye  than  in  reading  a  book.  By  its  aid  the  observer  fills  in 
the  outline  already  projected  on  the  paper. 

The  photograph  has  transported  us  already  so  near  the  sun's 
surface  that  we  have  seen  details  there  invisible  to  the  naked 
eye.  We  have  seen  that 
what  we  have  called  "spots" 
are  indeed  regions  whose 
actual  vastness  surpasses 
the  vague  immensity  of  a 

dream,  and  it  will  not  cause 

surprise  that  in  them  is  a     HB^»^BBBI^B«r      ' 
temperature  which  also  sur- 
passes greatly  that  of  the 

hottest  furnace.     We  shall  i 

see  later,  in  fact,  that  the 
whole  surface  is  composed 

largely     of    metals      turned       FIG.  is.  — "THE  PLUME"  SPOT  OF  MARCH  5  AND 

into  vapor  in  this  heat,  and        "' 1873'    (FKOM  AN  °"01"Al  DRAWIXO  BY  8'  "' 

LANGrLEl[  •  I 

that    if   we    could    indeed 

drop  our  great  globe  itself  upon  the  sun,  it  would  be  dissipated 
as  a  snow-flake.  Now,  we  cannot  suppose  this  great  space  is 
fully  described  when  we  have  divided  it  into  the  penumbra, 
umbra,  and  nucleus,  or  that  the  little  photograph  has  shown  us 
all  there  is,  and  we  rather  anticipate  that  these  great  spaces  must 
be  filled  with  curious  things,  if  we  could  get  near  enough  to  see 
them.  We  cannot  advantageously  enlarge  our  photograph  fur- 
ther; but  if  we  could  really  come  closer,  we  should  have  the 
nearer  view  that  the  work  at  Allegheny,  I  have  just  alluded  to, 


20  THE  NEW  ASTRONOMY. 

now  affords.  The  drawing  (Fig.  15)  of  the  central  part  of 
the  same  great  spot,  already  cited,  was  made  on  the  21st  of  Sep- 
tember, 1870,  and  may  be  compared  with  the  photograph  of 
that  day.  We  have  now  a  greatly  more  magnified  view  than 
before,  but  it  is  not  blurred  by  the  magnifying,  and  is  full  of 
detail.  We  have  been  brought  within  two  hundred  thousand 
miles  of  the  sun,  or  rather  less  than  the  actual  distance  of  the 
moon,  and  are  seeing  for  ourselves  what  was  a  few  years  since 
thought  out  of  the  reach  of  any  observer.  See  how  full  of  intri- 
cate forms  that  void,  black,  umbral  space  in  the  photograph  has 
become !  The  penumbra  is  filled  with  detail  of  the  strangest 
kind,  and  there  are  two  great  "  bridges,"  as  they  are  called, 
which  are  almost  wholly  invisible  in  the  photograph.  Notice 
the  line  in  one  of  the  bridges  which  follows  its  sinuosities 
through  its  whole  length  of  twelve  thousand  miles,  making  us 
suspect  that  it  is  made  up  of  smaller  parts  as  a  rope  is  made  up 
of  cords  (as,  in  fact,  it  is) ;  and  look  at  the  end,  where  the  cords 
themselves  are  unravelled  into  threads  fine  as  threads  of  silk, 
and  these  again  resolved  into  finer  fibres,  till  in  more  and  more 
web-like  fineness  it  passes  beyond  the  reach  of  sight !  I  am 
speaking,  however,  here  rather  of  the  wonderful  original,  as  I  so 
well  remember  it,  than  of  what  my  sketch  or  even  the  engraver's 
skill  can  render. 

Next  we  have  quite  another  "  spot "  belonging  to  another 
year  (1873).  First,  there  is  a  view  (Fig.  17)  of  the  sun's  disk 
with  the  spot  on  it  (as  it  would  appear  in  a  small  telescope),  to 
show  its  relative  size,  and  then  a  larger  drawing  of  the  spot 
itself  (Fig.  16),  on  a  scale  of  twelve  thousand  miles  to  the  inch, 
so  that  the  region  shown  to  the  reader's  eyes,  though  but  a 
"spot"  on  the  sun,  covers  an  area  of  over  one  billion  square 
miles,  or  more  than  five  times  the  entire  surface  of  the  earth, 
land,  and  water.  To  help  us  to  conceive  its  vastness,  I  have 
drawn  in  one  corner  the  continents  of  North  and  South  America 


FIG.    19. —TYPICAL    SUN    SPOT    OF    DECEMBER,    1873. 

(REDUCED  FROM  AN  ORIGINAL  DRAWING  BY  s.  P.  LANGLEY.) 


/^5^ 

^UNIVERSITY 


SPOTS   ON  THE  SUN.  23 

on  the  same  scale  as  the  "spot."  Notice  the  evidence  of  solar 
whirlwinds  and  the  extraordinary  "plume"  (Fig.  16),  which  is  a 
something-  we  have  no  terrestrial  simile  for.  The  appearance  of 
the  original  would  have  been  described  most  correctly  by  sucli 
incongruous  images  as  "  leaf-like  "  and  "  crystalline  "  and  "  flame- 
like  ;  "  and  even  in  this  inadequate  sketch  there  may  remain 
some  faint  suggestion  of  the  appearance  of  its  wonderful  arche- 


FIG.  '20.  —  FROST    CRYSTAL. 


type,  which  was  indeed  that  of  a  great  flame  leaping  into  spires 
and  viewed  through  a  window  covered  with  frost  crystals. 
Neither  "frost"  nor  "flame"  is  really  there,  but  we  cannot 
avoid  this  seemingly  unnatural  union  of  images,  which  was  fully 
justified  by  the  marvellous  thing  itself.  The  reader  must  bear  in 
mind  that  the  whole  of  this  was  actually  in  motion,  not  merely 
turning  with  the  sun's  rotation,  but  whirling  and  shifting  within 
itself,  and  that  the  motion  was  in  parts  occasionally  probably  as 
high  as  fifty  miles  per  second,  —  per  second,  remember,  not  per 


24 


THE  NEW  ASTRONOMY. 


hour,  —  so  that  it  changed  under  the  gazer's  eyes.  The  hook- 
shaped  prominence  in  the  lower  part  (actually  larger  than  the 
United  States)  broke  up  and  disappeared  in  about  twenty  min- 
utes, or  while  the  writer  was  engaged  in  drawing  it.  The 
imagination  is  confounded  in  an  attempt  to  realize  to  itself  the 
true  character  of  such  a  phenomenon. 

"  On  page  19  is  a  separate  view  of  the  plume  (Fig.  18),  a  fac- 
simile of  the  original  sketch,  which  was  made  with  the  eye  at 

the  telescope.  The  pointed 
or  flame-like  tips  are  not  a 
very  common  form,  the  ter- 
minals being  more  com- 
monly clubbed,  like  those 
in  Father  Secchi's  "  branch 
of  cactus "  type  given  on 
page  12.  It  must  be  borne 
in  mind,  too,  if  the  drawing 
does  not  seem  to  contain 
all  that  the  text  implies, 
that  there  were  but  a  few 
minutes  in  which  to  attempt 
to  draw,  where  even  a 
skilled  draughtsman  might  have  spent  hours  on  the  details 
momentarily  visible,  and  that  much  must  be  left  to  memory. 
The  writer's  note-book  at  the  time  contains  an  expression  of 
despair  at  his  utter  inability  to  render  most  of  what  he  saw. 

Let  us  now  look  at  another  and  even  more  wonderful  exam- 
ple. Fig.  19  shows  part  of  a  great  spot  which  the  writer  drew 
in  December,  1873,  when  the  rare  coincidence  happened  of  a 
fine  spot  and  fine  terrestrial  weather  to  observe  it  in.  In  this, 
as  well  as  in  the  preceding  drawing,  the  pores  which  cover  the 
sun's  surface  by  millions  may  be  noted.  The  luminous  dots 
which  divide  them  are  what  Xasmyth  imperfectly  saw,  but  we 


FIG.  21. CYCLONE  SPOT.    (DRAWN  BY  FATHER 

8ECCHI.) 


SPOTS    ON   THE  SUN. 


are  hardly  more  able  than  he  to  say  what  they  really  are. 
Each  of  these  countless  "  dots "  is  larger  than  England,  Scot- 
land, and  Ireland  together  !  The  wonderful  "  crystalline"  struc- 
ture in  the  centre  cannot  be  a  real  crystal,  for  it  is  ten  times  the 
area  of  Europe,  and  changed  slowly  while  I  drew  it;  but  the 
reader  may  be  sure  that  its  resemblance  to  some  crystallizations 
has  not  been  in  the  least  exaggerated.  I  have  sought  to  study 
various  actual  crystals  for  comparison,  but  found  none  quite 
satisfactory.  That  of  sal- 
ammoniac  in  some  re- 
mote way  resembles  it, 
as  Secclii  says  ;  but  per- 
haps the  frost  crystals  on 
a  window-pane  are  bet- 
ter. Fig.  20  shows  one 
selected  among  several 
windows  T  had  photo- 
graphed in  a  preceding 
winter,  which  has  some 
suggestions  of  the  so- 
called  crystalline  spot- 
forms  in  it,  but  which 
lacks  the  filamentary 
thread-like  components  presently  described.  Of  course  the 
reader  will  understand  that  it  is  given  as  a  suggestion  of  the 
appearance  merely,  and  that  no  similarity  of  nature  is  meant 
to  be  indicated. 

There  were  wonderful  fern-like  forms  in  this  spot,  too,  and 
an  appearance  like  that  of  pine-boughs  covered  with  snow ;  for, 
strangely  enough,  the  intense  whiteness  of  the  solar  surface  in 
the  best  telescopes  constantly  suggests  cold.  I  have  had  the 
same  impression  vividly  in  looking  at  the  immense  masses  of 
molten-white  iron  in  a  great  puddling-furnace.  The  salient 


\ 


FIG.   22. —  SPOT   OF  MARCH   31,   1875.      (FROM   AN 
ORIGINAL  DRAWING  BY  S.  P.  LANGLEY.) 


26  THE  NEW  ASTRONOMY. 

feature  here  is  one  very  difficult  to  see,  even  in  good  telescopes, 
but  one  which  is  of  great  interest.  It  has  been  shown  in  the 
previous  drawings,  but  we  have  not  enlarged  on  it.  Every- 
where in  the  spot  are  long  white  threads,  or  filaments,  lying 
upon  one  another,  tending  in  a  general  sense  toward  the  centre, 
and  each  of  which  grows  brighter  toward  its  inner  extremity. 
These  make  up,  in  fact,  as  we  now  see,  the  penumbra,  or  outer 
shade,  and  the  so-called  "crystal"  is  really  affiliated  to  them. 
Besides  this,  on  closer  looking  we  see  that  the  inner  shade,  or 
umbra,  and  the  very  deepest  shades,  or  nuclei,  are  really  made 
of  them  too.  We  can  look  into  the  dark  centre,  as  into  a  funnel, 
to  the  depth  of  probably  over  five  thousand  miles ;  but  as  far  as 
we  may  go  down  we  come  to  no  liquid  or  solid  floor,  and  see 
only  volumes  of  whirling  vapor,  disposed  not  vaguely  like  our 
clouds,  but  in  the  singularly  definite,  fern-like,  flower-like  forms 
which  are  themselves  made  of  these  "  filaments,"  each  of  which 
is  from  three  to  five  thousand  miles  long,  and  from  fifty  to  two 
hundred  miles  thick,  and  each  of  which  (as  we  saw  in  the  first 
spot)  appears  to  be  made  up  like  a  rope  of  still  finer  and  finer 
strands,  looking  in  the  rare  instants  when  irradiation  makes  an 
isolated  one  visible,  like  a  thread  of  gossamer  or  the  finest  of 
cobweb.  These  suggest  the  fine  threads  of  spun  glass ;  and 
here  there  is  something  more  than  a  -mere  resemblance  of  form, 
for  both  appear  to  have  one  causal  feature  in  common,  due  to  a 
viscous  or  "  sticky "  fluid ;  for  there  is  much  reason  to  believe 
that  the  solar  atmosphere,  even  where  thinner  than  our  own  air, 
is  rendered  viscous  by  the  enormous  heat,  and  owes  to  this  its 
tendency  to  pull  out  in  strings  in  common  with  such  otherwise 
dissimilar  things  as  honey,  or  melted  sugar,  or  melted  glass. 

We  may  compare  those  mysterious  things,  the  filaments,  to 
long  grasses  growing  in  the  bed  of  a  stream,  which  show  us  the 
direction  and  the  eddies  of  the  current.  The  likeness  holds  in 
more  ways  than  one.  They  are  not  lying,  as  it  were,  flat  upon 


SPOTS   ON  THE  SUN. 


27 


the  surface  of  the  water,  but  within  the  medium ;  and  they  do 
not  stretch  along  in  any  one  plane,  but  they  bend  down  and  up. 
Moreover,  they  are,  as  we  see,  apparently  rooted  at  one  end,  and 
their  tips  rise  above  the  turbid  fluid  and  grow  brighter  as  they 
are  lifted  out  of  it.  But  perhaps  the  most  significant  use  of  the 
comparison  is  made  if  we  ask  whether  the  stream  is  moving  in 
an  eddy  like  a  whirlpool  or  boiling  up  from  the  ground.  The 
question  in  other  words  is,  "  Are  these  spots  themselves  the  sign 


FIG.  23.  —  CIRROUS  CLOUD.   (FROM  A  PHOTOGRAPH.) 

of  a  mere  chaotic  disturbance,  or  do  they  show  us  by  the  dis- 
position of  these  filaments  that  each  is  a  great  solar  maelstrom, 
carrying  the  surface  matter  of  the  sun  down  into  its  body  I  or,  -s 
finally,  are  they  just  the  opposite,  —  something  comparable  to 
fiery  fountains  or  volcanoes  on  the  earth,  throwing  up  to  the   ^ 
surface  the  contents  of  the  unknown  solar  interior!" 

Before  we  try  to  answer  this  question,  let  us  remember  that 
the  astonishing  rapidity  with  which  these  forms  change,  and  still 
more  the  fact  that  they  do  not  by  any  means  always  change  by 
a  bodily  removal  of  one  part  from  another,  but  by  a  dissolving 
away  and  a  fading  out  into  invisibility,  like  the  melting  of  a 
cloud  into  thin  air,  —  let  us  remember  that  all  this  assimilates 


28 


THE  NEW  ASTRONOMY. 


them  to  something  cloud-like  and  vaporous,  rather  than  crystal- 
line, and  that,  as  we  have  here  seen,  we  can  ourselves  pronounce 
from  such  results  of  recent  observation  that  these  are  not  lumps 
of  scoria?  floating  on  the  solar  furnace  (as  some  have  thought 
them),  and  still  less,  literal  crystals.  We  can  see  for  ourselves, 
I  believe,  that  so  far  there  is  no  evidence  here  of  any  solid,  or 
even  liquid,  but  that  the  surface  of  the  sun  is  purely  vaporous. 
Fig.  23  shows  a  cirrous  cloud  in  our  own  atmosphere,  caught 

for  us  by  photography, 
and  which  the  reader 
will  find  it  interesting 
to  compare  with  the  ap- 
parently analogous  solar 
cloud-forms. 

"  Vaporous,"  we  call 
them,  for  want  of  a  bet- 
ter word,  but  without 
meaning  that  it  is  like 
the  vapor  of  our  clouds. 
There  is  no  exact  terres- 
trial analogy  for  these  ex- 
traordinary forms,  which 
are  in  fact,  as  we  shall 
see  later,  composed  of  iron  and  other  metals  —  not  of  solid 
iron  nor  even  of  liquid,  but  iron  heated  beyond  even  the 
liquid  state  to  that  of  iron-steam  or  vapor. 

\Yith  all  this  in  mind,  let  us  return  to  the  question,  "  Are 
the  spots,  these  gigantic  areas  of  disturbance,  comparable  to 
whirlpools  or  to  volcanoes  ?  "  It  may  seem  unphilosophical  to 
assume  that  they  are  one  or  the  other,  and  in  fact  they  may 
possibly  be  neither;  but  it  is  certain  that  the  surface  of  the  sun 
would  soon  cool  from  its  enormous  temperature,  if  it  were  not 
supplied  with  fresh  heat,  and  it  is  almost  certain  that  this  heat 


X 


FIG.  24. —  SPOT   OP    MARCH   31,   1875.      (FROM   AN 
ORIGINAL   DRAWING    BY    S.  P.  LANGLEY.) 


SPOTS   ON  THE  SUN. 


29 


is  drawn  from  the  interior.     As  M.  Faye  has  pointed  out,1  there 

Hiii«t  be  a  circulation  up  and  down,  the  cooled  products  being  ^ 

carried  within,  heated  and  brought  out  again,  or  the  sun  would, 

however  hot,  grow  cold  outside;  and,  what  is  of  interest  to  us, 

the  earth  would  grow  cold 

also,  and  we  should  all  die. 

Xo  one,  I  believe,  who  has 

studied    the    subject,    will 

contradict    the    statement 

that   if  the    sun's    surface 

were    absolutely    cut    off 

from  any  heat  supply  from 

the  interior,  organic  life  in 

general    upon     the    earth 

(and   Our   Own   life  in  par-     FiG..25.- TYPICAL  ILLUSTRATION  OP  FATE'S  THEORY. 

ticular)  would  cease  much 

within  a  month.  This  solar  circulation,  then,  is  of  nearly  as  much 
consequence  to  us  as  that  of  our  own  bodies,  if  we  but  knew  it ; 
and  now  let  us  look  at  the  spots  again  with  this  in  mind. 

Fig.  21  shows  a  drawing  by  Father  Secchi  of  a  spot  in  1854 ; 
and  it  is,  if  un exaggerated,  quite  the  most  remarkable  case  of 
distinct  cyclonic  action  recorded.  I  say  "if  unexaggerated " 
because  there  is  a  strong  tendency  in  most  designers  to  select 
what  is  striking  in  a  spot,  and  to  emphasize  that  unduly,  even 
when  there  is  no  conscious  disposition  to  alter.  Every  one  who 
sketches  may  see  a  similar  unconscious  tendency  in  himself  or 
herself,  shown  in  a  disposition  to  draw  all  the  mountains  and 
hills  too  high,  —  a  tendency  on  which  Ruskin,  I  think,  has 
remarked.  In  drawings  of  the  sun  there  is  a  strong  temptation 
to  exaggerate  these  circular  forms,  and  we  must  not  forget  this 
in  making  up  the  evidence.  There  is  great  need  of  caution,  then, 
in  receiving  such  representations;  but  there  certainly  are  forms 
which  seem  to  be  clearly  due  to  cyclonic  action.  They  are 

1  To  Mr.  Herbert  Spencer  must  be  assigned  the  earliest  suggestion  of  the  necessity 
of  such  a  circulation. 


30 


THE  NEW  ASTRONOMY. 


usually  scattered,  however,  through  larger  spots,  and  I  have 
never,  in  all  my  study  of  the  sun,  seen  one  such  complete  type 
of  the  cyclone  spot  as  that  first  given  from  Secchi.  Instances 
where  spots  break  up  into  numerous  subdivisions  by  a  process 
of  "  segmentation  "  under  the  apparent  action  of  separate  whirl- 
winds are  much  more  common.  I  have  noticed,  as  an  apparent 
effect  of  this  segmentation,  what  I  may  call  the  "honeycomb 
structure  "  from  its  appearance  with  low  powers,  but  which  with 
higher  ones  turns  out  to  be  made  up  of  filamentary  masses  dis- 
posed in  circular  and  ovoid  curves,  often  apparently  overlying 
one  another,  and  frequently  presenting  a  most  curious  resem- 
blance to  vegetable  forms,  though  we  appear  to  see  the  real 
agency  of  whirlwinds  in  making  them.  I  add  some  transcripts 
of  my  original  pencil  memoranda  themselves,  made  with  the  eye 

at  the  telescope,  which, 
though  not  at  all  finished 
drawings,  may  be  trusted 
the  more  as  being  quite 
literal  transcripts  at  first 
hand. 

Figs.  22  and  24,  for  in- 
stance, are  two  sketches  of 
a  little  spot,  showing  what, 
with  low  powers,  gives  the 
appearance  I  have  called 
the  honeycomb  structure, 
but  which  we  see  here  to 
be  due  to  whirls  which  have 
disposed  the  filaments  in  these  remarkable  forms.  The  first  was 
drawn  at  eleven  in  the  forenoon  of  March  31,  1875,  the  second 
at  three  in  the  afternoon  of  the  same  day.  The  scale  of  the 
drawing  is  fifteen  thousand  miles  to  the  inch,  and  the  changes 
in  this  little  spot  in  these  few  hours  imply  a  cataclysm  compared 


FIG.  ifi.  —  SPOT  OF  OCT.  13,  1876.      (FROM  ORIGINAL 
DRAWING    BY   8.  P.  LANGLEY.) 


SPOTS   ON  THE  SUN.  31 

with  which  the  disappearance  of  the  American  continent  from  the 
earth's  surface  would  be  a  trifle. 

The  very  act  of  the  solar  whirlwind's  motion  seemed  to  pass 
before  my  eyes  in  some  of  these  sketches ;  for  while  drawing 
them  as  rapidly  as  possible,  a  new  hole  would  be  formed  where 
there  was  none  before,  as  if  by  a  gigantic  invisible  auger  boring 
downward. 

M.  Faye,  the  distinguished 
French  astronomer,  believes 
that,  owing  to.  the  fact  that 
different  zones  of  -the  sun 
rotate  faster  -than  others, 
whirlwinds  analogous  to  our 
terrestrial  cyclones,  but  on  a 
vaster  scale,  are  set  in  mo- 
tion, and  suck  down  the 
cooled  vapors  of  the  solar 
surface  into  its  interior,  to  be 
heated  and  returned  again, 
thus  establishing  a  circula- 
tion which  keeps  the  surface 
from  cooling  down.  He 

points     OUt     that     We     should    FIG.  2:.—  PHOTOGRAPH  OF  EDGE  OF  SUN.    (BY  PER- 
MISSION OF  WARREN  DE  LA  RL'E,  LONDON.) 

not  conclude  that  these  whirl- 
winds are  not  acting  everywhere,  merely  because  our  bird's- 
eye  view  does  not  always  show  them.  We  see  that  the  spinning 
action  of  a  whirlpool  in  water  becomes  more  marked  as  we  go 
below  the  surface,  which  is  comparatively  undisturbed,  and  we 
often  see  one  whirl  break  up  into  several  minor  ones,  but  all 
sucking  downward  and  never  upward.  According  to  M.  Faye, 
something  very  like  this  takes  place  on  the  sun,  and  in  Fig.  25 
he  gives  this  section  to  show  what  he  believes  to  occur  in  the 
case  of  a  spot  which  has  "  segmented,"  or  divided  into  two,  like 


32  THE  NEW  ASTRONOMY. 

the  one  whose  (imaginary)  section  is  shown  above  it.  This 
theory  is  to  be  considered  in  connection  with  such  drawings 
as  we  have  just  shown,  which  are  themselves,  however,  no  way 
dependent  on  theory,  but  transcripts  from  Nature. 

I  do  not  here  either  espouse  or  oppose  the  "  cyclonic"  theory, 
but  it  is  hardly  possible  for  any  one  who  has  been  an  eyewitness 
of  such  things  to  refuse  to  regard  some  such  disturbance  as  a 
real  and  efficient  cause  in  such  instances  as  this. 

Fig.  26,  on  nearly  the  same  scale  as  the  last,  shows  a  spot 
which  was  seen  on  Oct.  13,  1876.  It  looked  at  first,  in  the  tele- 
scope, like  two  spots  without  any  connection ;  then,  as  vision 
improved  and  higher  powers  were  employed,  the  two  were  seen 
to  have  a  subtle  bond  of  union,  and  each  to  be  filled  with  the 
most  curious  foliage-forms,  which  I  could  only  indicate  in  the 
few  moments  that  the  good  definition  lasted.  The  reader  may 
be  sure,  I  think,  that  there  is  no  exaggeration  of  the  curious 
shapes  of  the  original ;  for  I  have  been  so  anxious  to  avoid  the 
overstatement  of  curvature  that  the  error  is  more  likely  to  be  in 
the  opposite  direction. 

We  must  conclude  that  the  question  as  to  the  cyclonic 
hypothesis  cannot  yet  be  decided,  though  the  probabilities  from 
telescopic  evidence  at  present  seem  to  me  on  the  whole  in  favor 
of  M.  Faye's  remarkable  theory,  which  has  the  great  additional 
attraction  to  the  student  that  it  unites  and  explains  numerous 
other  quite  disconnected  facts. 

Turning  now  to  the  other  solar  features,  let  us  once  more 
consider  the  sun  as  a  whole.  Fig.  27  is  a  photograph  taken 
from  a  part  of  the  sun  near  its  edge.  We  notice  on  it,  what  we 
see  on  every  careful  delineation  of  the  sun,  that  its  general  sur- 
face is  not  uniformly  bright,  but  that  it  grows  darker  as  we 
approach  the  edge,  where  it  is  marked  by  whiter  mottlings  called 
fjirulse,  "something  in  the  sun  brighter  than  the  sun  itself,"  and 
looking  in  the  enlarged  view  which  we  present  of  one  of  them 


SPOTS   ON  THE  SUN. 


33 


(Fig.  28),  as  if  the  surface  of  partly  cooled  metal  in  a  caldron 
had  been  broken  into  fissures  showing  the  brighter  glow  beneath. 
These  "faculse,"  however,  are  really  above  the  solar  surface,  not 
below  it,  and  what  we  wish  to  direct  particular  attention  to  is 
that  darkening  toward  the  edge  which  makes  them  visible. 

This  is  very  significant,  but  its  full  meaning  may  not  at  first 
be  clear.     It  is  owing  to  an  atmosphere  which  surrounds  the^sun, 
as  the  air  does  the  earth. 
When  we  look  horizontally 
through  our  own  air,  as  at 

O  7 

sunrise  and  sunset,  we  gaze 
through  greater  thicknesses 
of  it  than  when  we  turn 
our  eyes  to  the  zenith.  So 
when  we. look  at  the  edge 
of  the  sun,  the  lin^  of  sight 
passes-  through  greater 
depths  of  this  solar  at- 
mosphere, and  it  dims  the 
light  shining  behind  it 
more  than  at  the  centre, 
where  it  is  thin. 

This  darkening  toward 


FIG.    28.  —  FACULA.       (FROM   A    DRAWING    BY 
CHACORNAC.) 


the  edge,  then,  means  that 
the  sun  has  an  atmosphere 

which  tempers  its  heat  to  us.  Whatever  the  sun's  heat  supply  is 
within  its  globe,  if  this  atmosphere  grow  thicker,  the  heat  is  more 
confined  within,  and  our  earth  will  grow  colder ;  if  the  solar  at- 
mosphere grow  thinner,  the  sun's  energy  will  be  expended  more 
rapidly,  and  our  earth  will  grow  hotter.  This  atmosphere,  then, 
is  in  considerable  part,  at  least,  the  subject  of  the  action  of  the 
spots;  this  is  what  they  are  supposed  to  carry  down  or  to 
spout  up. 

3 


34  THE  NEW  ASTRONOMY. 

We  shall  return  to  the  study  of  it  again ;  but  what  I  want  to 
point  out  now  is  that  the  temperature  of  the  earth,  and  even  the 
existence  of  man  upon  it,  depends  very  much  upon  this,  at  first 
sight,  insignificant  phenomenon.  What,  then,  is  the  solar  atmos- 
phere? Is  it  a  permanent  thing?  Not  at  all.  It  is  more  light 
and  unsubstantial  than  our  own  air,  and  is  being  whirled  about 
by  solar  winds  as  ours  toss  the  dust  of  the  streets.  It  is  being 
sucked  down  within  the  body  of  the  sun  by  some  action  we  do 
not  clearly  understand,  and  returned  to  the  surface  by  some 
counter  effect  which  we  comprehend  no  better;  and  upon  this 
imperfectly  understood  exchange  depends  in  some  way  our  own 
safety. 

There  used  to  be  recorded  in  medical  books  the  case  of  a  boy 
who,  to  represent  Phoebus  in  a  Roman  mask,  was  gilded  all 
over  to  produce  the  effect  of  the  golden-rayed  god,  but  who  died 
in  a  few  hours  because,  all  the  pores  of  the  skin  being  closed  by 
the  gold-leaf,  the  natural  circulation  was  arrested.  We  can  count 
with  the  telescope  millions  of  pores  upon  the  sun's  surface,  which 
are  in  some  way  connected  with  the  interchange  which  has  just 
been  spoken  of;  and  if  this,  his  own  natural  circulation,  were 
arrested  or  notably  diminished,  we  should  see  his  face  grow  cold, 
and  know  that  our  own  health,  with  the  life  of  all  the  human 
race,  was  waiting  on  his  recovery. 


II. 

THE   SUN'S   SURROUNDINGS. 

AS  I  write  this,  the  fields  glitter  with  snow-crystals  in  the 
winter  noon,  and  the  eye  is  dazzled  with  a  reflection  of 
the  splendor  which  the  sun  pours  so  fully  into  every  nook  that 
by  it  alone  we  appear  to  see  everything. 

Yet,  as  the  day  declines,  and  the  glow  of  the  sunset  spreads 
up  to  the  zenith,  there  comes  out  in  it  the  white-shining  evening 
star,  which  not  the  light,  but  the  darkness,  makes  visible ;  and 
as  the  last  ruddy  twilight  fades,  not  only  this  neighbor- world, 
whose  light  is  fed  from  the  sunken  sun,  but  other  stars  appear, 
themselves  self-shining  suns,  which  were  above  us  all  through 
the  day,  unseen  because  of  the  very  light. 

As  night  draws  on,  we  may  see  the  occasional  flash  of  a 
shooting-star,  or  perhaps  the  auroral  streamers  spreading  over 
the  heavens ;  and  remembering  that  these  will  fade  as  the  sun 
rises,  and  that  the  nearer  they  are  to  it  the  more  completely 
they  will  be  blotted  out,  we  infer  that  if  the  sun  were  surrounded 
by  a  halo  of  only  similar  brightness,  this  would  remain  forever 
invisible,  —  unless,  indeed,  there  were  some  way  of  cutting  off 
the  light  from  the  sun  without  obscuring  its  surroundings.  But 
if  we  try  the  experiment  of  holding  up  a  screen  which  just  con- 
ceals the  sun,  nothing  new  is  seen  in  its  vicinity,  for  we  are  also 
lighted  by  the  neighboring  sky,  which  is  so  dazzlingly  bright 
with  reflected  light  as  effectually  to  hide  anything  which  may 
be  behind  it,  so  that  to  get  rid  of  this  glare  we  should  need  to 
hang  up  a  screen  outside  the  earth's  atmosphere  altogether. 


36  THE  NEW  ASTRONOMY. 

Nature  hangs  such  a  screen  in  front  of  the  earth  when  the 
moon  passes  between  it  and  the  sun ;  but  as  the  moon  is  far 
too  small  to  screen  all  the  earth  completely,  and  as  so  limited  a 
portion  of  its  surface  is  in  complete  shadow  that  the  chances  are 
much  against  any  given  individual's  being  on  the  single  spot 
covered  by  it,  many  centuries  usually  elapse  before  such  a  total 
eclipse  occurs  at  any  given  point ;  while  yet  almost  every  year 


FIG.  29.  —  LUNAR    CONE    SHADOW. 


there  may  be  a  partial  eclipse,  when,  over  a  great  portion  of  the 
earth  at  once,  people  may  be  able  to  look  round  the  moon's  edge 
and  see  the  sunlight  but  partly  cut  off.  Nearly  every  one,  then, 
has  seen  a  partial  eclipse  of  the  sun,  but  comparatively  few  a 
total  one,  which  is  quite  another  thing,  and  worth  a  journey 
round  the  world  to  behold ;  for  such  a  nimbus,  or  glory,  as  we 
have  suggested  the  possibility  of,  does  actually  exist  about  the 
sun,  and  becomes  visible  to  the  naked  eye  on  the  rare  occasions 
when  it  is  visible  at  all,  accompanied  by  phenomena  which  are 
unique  among  celestial  wonders. 

The  u  corona,"  as  this  solar  crown  is  called,  is  seen  during  a 
total  eclipse  to  consist  of  a  bright  inner  light  next  the  invisible 
sun,  which  melts  into  a  fainter  and  immensely  extended  radiance 
(the  writer  has  followed  the  latter  to  the  distance  of  about  ten 
million  miles),  and  all  this  inner  corona  is  filled  with  curious 


THE  SUN'S  SURROUNDINGS.  37 

*• 

detail.  All  this  is  to  be  distinguished  from  another  remarkable 
feature  seen  at  the  same  time ;  for  close  to  the  black  body  of  the 
moon  are  prominences  of  a  vivid  crimson  and  scarlet,  rising  up 
like  mountains  from  the  hidden  solar  disk,  and  these,  which  will 
be  considered  later,  are  quite  distinct  from  the  corona,  though 
seen  on  the  background  of  its  pearly  light. 

To  understand  what  the  lunar  screen  is  doing  for  us,  we  may 
imagine  ourselves  at  some  station  outside  the  earth,  whence  we 
should  behold  the  moon's  shadow  somewhat  as  in  Fig.  29, 
where  we  must  remember  that  since  the  lunar  orbit  is  not 
a  circle,  but  nearly  an  ellipse,  the  moon  is  at  some  times  far- 
ther from,  the  earth  than  at  others.  Here  the  extremity  of 
its  shadow  is  represented  as  just  touching  the  surface  of  the 
globe,  while  it  is  evident  that  if  the  moon  were  at  its  greatest 
distance,  its  shadow  might  come  to  a  point  before  reaching  the 
earth  at  all.  We  speak,  of  course,  only  of  the  central  cone  of 
shade ;  for  there  is  an  outer  one,  indicated  by  the  faint  dotted 
lines,  within  whose  much  mor,e  extended  limits  the  eclipse  is 
partial,  but  with  the  latter  we  have  at  present  nothing  to  do. 
The  figure  however,  for  want  of  room,  is  made  to  represent  the 
proportions  incorrectly,  the  real  ones  of  the  shadow  being  actu- 
ally something  like  those  of  a  sewing-needle,  —  this  very  long 
attenuated  shadow  sometimes,  as  we  have  just  said,  not  reaching 
the  earth  at  all,  and  when  it  does  reach  it,  covering  at  the  most 
a  very  small  region  indeed.  Where  this  point  touches,  and 
wherever  it  rests,  we  should,  in  looking  down  from  our  celestial 
station,  see  that  part  of  the  earth  in  complete  shadow,  appearing 
like  a  minute  dark  spot,  whose  lesser  diameter  is  seldom  over  a 
hundred  and  fifty  miles. 

The  eclipse  is  total  only  to  those  inhabitants  of  the  earth 
within  the  track  of  this  dark  spot,  though  the  spot  itself  travels 
across  the  earth  with  the  speed  of  the  moon  in  the  sky ;  so  that 
if  it  could  leave  a  mark,  it  would  in  a  few  hours  trace  a  dark 


38  THE  NEW  ASTRONOMY. 

line  across  the  globe,  looking1  like  a  narrow  black  tape  curving 
across  the  side  of  the  world  next  the  .sun.  In  Fig.  30,  for  in- 
stance, is  the  central  track  of  the  eclipse  of  July  29,  1878,  as  it 
would  be  visible  to  our  celestial  observer,  beginning  in  Alaska 
in  the  forenoon,  and  ending  in  the  Gulf  of  Mexico,  which  it 
reached  in  the  afternoon.  To  those  on  the  earth's  surface  within 
this  shadow  it  covered  everything  in  view,  and,  for  anything 
those  involved  in  it  could  see,  it  was  all-embracing  and  terrible, 
and  worthily  described  in  such  lines  as  Milton's, — 

"  As  when  the  sun  .  .  . 
In  dim  eclipse,  disastrous  twilight  sheds 
On  half  the  nations,  and  with  fear  of  change 
Perplexes  monarchs." 

We  may  enjoy  the  poet's  vision ;  but  here,  while  we  look 
down  on  the  whole  earth  at  once,  we  must  admit  that  the  actual 
area  of  the  " twilight"  is  very  small  indeed.  Within  this  area, 
however,  the  spectacle  is  one  of  which,  though  the  man  of  sci- 
ence may  prosaically  state  the  facts,  perhaps  only  the  poet  could 
render  the  impression. 

We  can  faintly  picture,  perhaps,  how  it  would  seem,  from  a 
station  near  the  lunar  orbit,  to  see  the  moon  —  a  moving  world 
—  rush  by  with  a  velocity  greater  than  that  of  the  cannon-ball 
in  its  swiftest  flight;  but  with  equal  speed  its  shadow  actually 
travels  along  the  earth.  And  now,  if  we  return  from  our  imagi- 
nary station  to  a  real  one  here  below,  we  are  better  prepared  to 
see  why  this  flying  shadow  is  such  a  unique  spectacle ;  for,  small 
as  it  may  be  when  seen  in  relation  to  the  whole  globe,  it  is 
immense  to  the  observer,  whose  entire  horizon  is  filled  with  it, 
and  who  sees  the  actual  velocity  of  one  of  the  heavenly  bodies, 
as  it  were,  brought  down  to  him. 

The  reader  who  has  ever  ascended  to  the  Superga,  at  Turin, 
will  recall  the  magnificent  view,  and  be  able  to  understand  the 
good  fortune  of  an  observer  (Forbes)  who  once  had  the  oppor- 


TlIK  SUN'S  SURROUNDINGS. 


39 


tunity  to  witness  thence  this  phenomenon,  and  under  a  nearly 
cloudless  sky.  "I  perceived,"  he  says,  "  in  the  southwest  a 
black  shadow  like  that  of  a  storm  about  to  break,  which  ob- 
scured the  Alps.  It  was  the  lunar  shadow  coming  toward  us." 
And  he  speaks  of  the  "  stupefaction "  -it  is  his  word  —  caused 
by  the  spectacle.  "I  confess,"  he  continues,  "it  was  the  most 
terrifying-  sight  I  ever  saw.  As  always  happens  in  the  cases  of 
sudden,  silent,  unexpected 
movements,  the  spectator 
confounds  real  and  relative 
motion.  I  felt  almost  gid- 
dy for  a  moment,  as  though 
the  massive  building1  under 

o 

me  bowed  on  the  side  of 
the  coming  eclipse."  An- 
other witness,  who  had 
been  looking  at  some 
bright  clouds  just  before, 
says:  "The  bright  cloud 
I  saw  distinctly  put  out 
like  a  candle.  The  rapid- 
ity of  the  shadow,  and  the 
intensity,  produced  a  feel- 
ing that  something  material  was  sweeping  over  the  earth  at  a 
speed  perfectly  frightful.  I  involuntarily  listened  for  the  rushing 
noise  of  a  mighty  wind." 

Each  one  notes  something  different  from  another  at  such  a 
time ;  and  though  the  reader  will  find  minute  descriptions  of  the 
phenomena  already  in  print,  it  will  perhaps  be  more  interesting 
if,  instead  of  citations  from  books,  I  invite  him  to  view  them 
with  me,  since  each  can  tell  best  what  he  has  personally  seen. 

I  have  witnessed  three  total  eclipses,  but  I  do  not  find  that 
repetition  dulls  the  interest.  The  first  was  that  of  1869,  which 


FIG.   30. — TRACK   OF   LUNAR   SHADOW. 


40 


THE  NEW  ASTRONOMY. 


passed  across  the  United  States  and  was  nearly  central  over 
Louisville.  My  station  was  on  the  southern  border  of  the 
eclipse  track,  not  very  far  from  the  Mammoth  Cave  in  Ken- 
tucky, and  I  well  remember  that  early  experience.  The  special 
observations  of  precision  in  which  I  was  engaged  would  not  inter- 
est the  reader ;  but  while  trying  to  give  my  undivided  attention 

to  these,  a  mental  photo- 
graph of  the  whole  spec- 
tacle seemed  to  be  taking 
without  my  volition.  First, 
the  black  body  of  the 
moon  advanced  slowly  on 
the  sun,  as  we  have  all 
seen  it  do  in  partial  eclipses, 
without  anything  notice- 
able appearing ;  nor  till  the 
sun  was  very  nearly  cov- 
ered did  the  light  of  day 

FIG.   31.-INKER    COROXA    ECLIPSE    OP    1869.       FROM         ab°Ut     U§       *****      ™<^      &' 
SHELBYVILLE   PHOTOGRAPH.       (ROYAL   ASTRONOM-         millislied.  But     wllCU     tll6 

ICAL  SOCIETY'S  MEMOIRS.) 

sun  s  face  was  reduced  to 

a  very  narrow  crescent,  the  change  was  sudden  and  startling, 
for  the  light  which  fell  on  us  not  only  dwindled  rapidly, 
but  became  of  a  kind  unknown  before,  so  that  a  pallid  ap- 
pearance overspread  the  face  of  the  earth  with  an  ugly  livid 
hue;  and  as  this  strange  wanness  increased,  a  cold  seemed 
to  come  with  it.  The  impression  was  of  something  unnatural; 
but  there  was  only  a  moment  to  note  it,  for  the  sun  went 
out  as  suddenly  as  a  blown-out  gas-jet,  and  I  became  as  sud- 
denly aware  that  all  around,  where  it  had  been,  there  had 
been  growing  into  vision  a  kind  of  ghostly  radiance,  composed 
of  separate  pearly  beams,  looking  distinct  each  from  each, 
as  though  the  black  circle  where  the  sun  once  was,  bristled 


THE  SUN'S  SURROUNDINGS.  41 

with  pale  streamers,   stretching  far    away  from  it  in   a  sort  of 
crown. 

This  was  the  mysterious  corona,  only  seen  during  the  brief 
moments  while  the  shadow  is  flying  overhead;  but  as  I  am 
undertaking  to  recall  faithfully  the  impressions  of  the  instant, 
I  may  admit  that  I  was  at  the  time  equally  struck  with  a  cir- 
cumstance that  may  appear  trivial 
in  description,  —  the  extraordinary 
globular  appearance  of  the  moon 
herself.  We  all  know  well  enough 
that  the  moon  is  a  solid  sphere, 
but  it  commonly  looks  like  a  bright, 
flat  circle  fastened  to  the  concave 
of  the  starry  vault ;  and  now,  ow- 
ing to  its  unwonted  illumination, 
the  actual  rotundity  was  seen  for 
the  first  time,  and  the  result  was 
to  show  it  as  it  really  is,  —  a 

monstrOUS,    Solid    globe,     Suspended         FIG-  32-  —  SKETCH  OF  OUTER  CORONA, 

1869.      (U.S.  COAST  SURVEY  REPORT.) 

by   some    invisible   support   above 

the  earth,  with  nothing  apparent  to  keep  it  from  tumbling  on 
us,  looking  at  the  moment  very  near,  and  more  than  anything 
else  like  a  gigantic  black  cannon-ball,  hung  by  some  miracle 
in  the  air  above  the  neighboring  cornfield.  But  in  a  few  sec- 
onds all  was  over;  the  sunlight  flashed  from  one  point  of  the 
moon's  edge  and  then  another,  almost  simultaneously,  like  sud- 
denly kindled  electric  lights,  which  as  instantly  flowed  into  one, 
and  it  was  day  again. 

I  have  spoken  of  the  " unnatural"  appearance  of  the  light 
just  before  totality.  This  is  not  due  to  excited  fancy,  for  there 
is  something  so  essentially  different  from  the  natural  darkness 
of  twilight,  that  the  brute  creation  shares  the  feeling  with  us. 
Arago,  for  instance,  mentions  that  in  the  eclipse  of  1842,  at 


42  THE  NEW  ASTRONOMY. 

Perpignan,  where  he  was  stationed,  a  dog  which  had  been  kept 
from  food  twenty-four  hours  was,  to  test  this,  thrown  some  bread 
just  before  " totality"  began.  The  dog  seized  the  loaf,  began 
to  devour  it  ravenously,  and  then,  as  the  appearance  already 
described  came  on,  he  dropped  it.  The  darkness  lasted  some 
minutes,  but  not  till  the  sun  came  forth  again  did  the  poor  crea- 
ture return  to  the  food.  It  is  no  wonder,  then,  that  men  also, 
whether  educated  or  ignorant,  do  not  escape  the  impression.  A 
party  of  the  courtiers  of  Louis  XV.  is  said  to  have  gathered 
round  Cassini  to  witness  an  eclipse  from  the  terrace  of  the  Paris 
observatory,  and  to  have  been  laughing  at  the  populace,  whose 
cries  were  heard  as  the  light  began  to  fade ;  when,  as  the  unnat- 
ural gloom  came  quickly  on,  a  sudden  silence  fell  on  them  too, 
the  panic  terror  striking  through  their  laughter.  Something 
common  to  man  and  the  brute  speaks  at  such  times,  if  never 
before  or  again ;  something  which  is  not  altogether  physical 
apprehension,  but  more  like  the  moral  dismay  when  the  shock 
of  an  earthquake  is  felt  for  the  first  time,  and  we  first  know  that 
startling  doubt,  superior  to  reason,  whether  the  solid  frame  of 
earth  is  real,  and  not  "  baseless  as  the  fabric  of  a  vision." 

But  this  is  appealing  for  illustration  to  an  experience  which 
most  readers  have  doubtless  been  spared,1  and  I  wotild  rather 
cite  the  lighter  one  of  our  central  party  that  day,  a  few  miles 
north  of  me,  at  Shelby ville.  In  this  part  of  Kentucky  tin- 
colored  population  was  large,  and  (in  those  days)  ignorant  of 
everything  outside  the  life  of  the  plantation,  from  which  they 
had  only  lately  been  emancipated.  On  that  eventful  8th  of 
August  they  came  in  great  numbers  to  view  the  enclosure  and 
the  tents  of  the  observing  party,  and  to  inquire  the  price  of  the 
show.  On  learning  that  they  might  see  it  without  charge  from 
the  outside,  a  most  unfavorable  opinion  was  created  among 
them  as  to  the  probable  merits  of  so  cheap  a  spectacle,  and 

1  This  was  written  before  the  "  Charleston  earthquake"  occurred. 


THE  SUN'S  SURROUNDINGS.  43 

they  crowded  the  trees  about  the  camp,  shouting  to  each  other 
sarcastic  comments  on  the  inferior  interest  of  the  entertainment. 
"  Those  trees  there,"  said  one  of  the  observers  to  me  the  next 
day,  "  were  black  with  thern^  and  they  kept  up  their  noise  till 
near  the  last,  when  they  suddenly  stopped,  and  all  at  once,  and 
as  l  totality '  came,  we  heard  a  wail  and  a  noise  of  tumbling,  as 


FIG.  33. —  TACCHINl's  DRAWING  OF  CORONA  OF  1870. 
(SECCHI'S  "LE  SOLEIL.") 

though  the  trees  had  been  shaken  of  their  fruit,  and  then  the 
boldest  did  not  feel  safe  till  he  ;was  under,  his  own  bed  in  his 
own  calkin." 

It  is  impossible  to  give  an  exact  view  of  what  our  friends  at 
Shelbyville  saw,  for  no  drawings  made  there  appear  to  have 
been  preserved,  and  photography  at  that  time  could  only  indi- 
cate feebly  the  portion  of  the  corona  near  the  sun  where  it  is 
brightest.  Fig.  31  is  a  fac-simile  of  one  of  the  photographs 
taken  on  the  occasion,  which  is  interesting  perhaps  as  one  of 


44 


THE  NEW  ASTRONOMY. 


the  earl}7  attempts  in  this  direction,  for  comparison  with  later 
ones ;  but  as  a  picture  it  is  very  disappointing,  for  the  whole 
structure  of  the  outer  corona  we  have  alluded  to  is  missed  alto- 
gether, the  plate  having  taken  no  impression  of  it. 

A  drawing  (Fig.  32)  made  by  another  observer,  Mr.  M'Leod, 
at  Springfield,  represents  more  of  the  outer  structure ;  but  the 
reader  must  remember  that  all  drawings  must,  in  the  nature  of 
the  case  (since  there  are  but  two  or  three  minutes  to  sketch  in), 
be  incomplete,  whatever  the  artist's  skill. 

Up  to  this  time  it  was  still  doubtful,  not  only  what  the  co- 
rona was,  but  where  it  was ;  whether  it  was  a  something  about 
the  sun  or  moon,  or  whether,  indeed,  it  might  not  be  in  our 
own  atmosphere.  The  spectroscopic  observations  of  Professors 
Young  and  Harkness  at  this  same  eclipse  of  a  green  line  in  its 
spectrum,  due  to  some  glowing  gas,  showed  conclusively  that 
it  was  largely,  at  any  rate,  a  solar  appendage,  and  partly,  at 

least,  self-luminous;  and  these  and 
other  results  having  awakened  general 
discussion  among  astronomers  in  Eu- 
rope as  well  as  at  home,  the  United 
States  Government  sent  an  expedi- 
tion, under  the  direction  of  the  late 
Professor  Pierce,  to  observe  an  eclipse 
which  in  the  next  year,  on  Dec.  8, 
1870,  was  total  in  the  south  of  Spain. 
There  were  three  parties ;  and  of  the 
most  western  of  these,  which  was  at 
Xeres  under  the  charge  of  Professor  Winlock,  I  was  a  member. 

The  duration  of  totality  was  known  beforehand.  It  would 
last  two  minutes  and  ten  seconds,  and  to  secure  what  could  be 
seen  in  this  brief  interval  we  crossed  the  ocean.  Our  station 
was  in  the  midst  of  the  sherry  district,  and  a  part  of  the  instru- 
ments were  in  an  orange-grove,  where  the  ground  was  covered 


FIO.  34. — WATSON'S  NAKED-EYE  DRAWING 
OF  CORONA  OF  1870.  (U.  8.  COAST  SUR- 
VEY REPORT.) 


FIG.  35.  — PHOTOGRAPH  SHOWING  COMMENCEMENT  OF  OUTER  CORONA. 
(ROYAL  ASTRONOMICAL  SOCIETY'S  MEMOIRS.) 


THE  SUN'S  SURROUNDINGS.  47 

with  the  ripe  fallen  fruit,  while  the  olive  and  vine  about  us  in 
December  reminded  us  of  the  distance  we  had  come  to  gather 
the  results  of  so  brief  an  opportunity. 

To  prepare  for  it,  we  had  all  arrived  on  the  ground  some 
weeks  beforehand,  and  had  been  assiduously  busy  in  installing 
the  apparatus  in  the  observing  camp,  which  suggested  that  of  a 
small  army,  the  numerous  instruments,  some  of  them  of  consid- 
erable size,  —  equatorials,  photographic  apparatus,  polariscopes, 
photometers,  and  spectroscopes,  —  being  under  tents,  the  fronts 
of  which  could  be  lifted  when  the  time  came  for  action. 

To  the  equatorial  telescopes  photographic  cameras  are  at- 
tached instead  of  the  eye-pieces,  in  the  hope  that  the  corona 
may  be  made  to  impress  itself  on  the  plate  instead  of  on  the 
eye.  The  eye  is  an  admirable  instrument  itself,  no  doubt ;  but 
behind  it  is  a  brain,  perhaps  overwrought  with  excitement,  and 
responding  too  completely  to  the  nervous  tension  which  most 
of  us  experience  when  those  critical  moments  are  passing  so 
rapidly.  The  camera  can  see  far  less  of  the  corona  than  the 
man,  but  it  has  no  nerves,  and  what  it  sets  down  we  may 
rely  on. 

At  such  a  time  each  observer  has  some  particular  task 
assigned  to  him,  on  which,  if  wise,  he  has  drilled  himself  for 
weeks  beforehand,  so  that  no  hesitation  or  doubt  may  arise  in 
the  moment  of  action ;  and  his  attention  is  expected  to  be  de- 
voted to  this  duty  alone,  which  may  keep  him  from  noting  any 
of  the  features  which  make  the  occasion  so  impressive  as  a 
spectacle.  Most  of  my  own  particular  work  was  again  of  a 
kind  which  would  not  interest  the  reader. 

Apart  from  this,  I  can  recall  little  but  the  sort  of  pain  of 
expectation,  as  the  moment  approached,  till  within  a  minute 
before  totality  the  hum  of  voices  around  ceased,  and  an  utter 
and  most  impressive  silence  succeeded,  broken  only  by  a  low 
"Ah!"  from  the  group  without  the  camp,  when  the  moment 


48  THE  NEW  ASTRONOMY. 

came.  I  remember  that  the  clouds,  which  had  hung  over  the 
sun  while  the  moon  was  first  advancing  on  its  body,  cleared. 
away  before  the  instant  of  totality,  so  that  the  last  thing  I  saw 
was  a  range  of  mountains  to  the  eastward  still  bright  in  the 
light ;  then,  the  next  moment,  the  shadow  rushed  overhead  and 
blotted  out  the  distant  hills,  almost  before  I  could  turn  my  face 
to  the  instrument  before  me. 


FIG.  36.  —  ECLIPSE  OF  18.")7,  DRAWING  BY  LIAIS.     (ROYAL  ASTRONOMICAL 
SOCIETY'S  MEMOIRS.) 

The  corona  appeared  to  me  a  different  thing  from  what  it  did 
the  year  before.  It  was  apparently  confined  to  a  pearly  light  of 
a  roughly  quadrangular  shape,  close  to  the  limb  of  the  sun, 
broken  by  dark  rifts  (one  of  which  was  a  conspicuous  object)  ; 
while  within,  and  close  to  the  limb,  was  what  looked  like  a 
mountain  rising  from  the  hidden  sun,  of  the  color  of  the  richest 
tint  we  should  see  in  a  rose-leaf  held  up  against  the  light, 
while  others  were  visible  of  an  orange-scarlet.  After  \\  short 
scrutiny  I  turned  to  my  task  of  analyzing  the  nature  of  the 
white  light. 


THE  SUN'S  SURROUNDINGS. 


49 


The  seconds  fled,  the  light  broke  out  again,  and  so  did  the 
hubbub  of  voices,  —  it  was  all  over,  and  what  had  been  missed 
then  could  not  be  recovered.     The  sense  of  self-reproach  for 
wasted  opportunity  is  a  common  enough  feeling  at  this  time, 
though  one  may  have  done  his  best,  so  little  it  seems  to  each 
he  has  accomplished ;  but  when  all  the  results  had  been  brought 
together,  we  found  that  the 
spectroscopes,  cameras,  and 
polariscopes  had  each  done 
their  work,  and  the  journey 
had  not  been  taken  in  vain. 
In  one  point  only  we  all 
differed,  and  this  was  about 
the  direct  ocular  evidence,         J| 
for   each   seemed   to  have 
seen  a  different  corona,  and 
the  drawings  of  it  were  sin- 
gularly unlike.     Here  are 
two  (Figs.  33  and  34)  taken 
at  this  eclipse  at  the  same 
time,  and  from  neighboring 
stations,  by  two   most   experienced    astronomers,  Tacchini  and 
Watson.     No  one  could  guess  that  they  represented  the  same 
object,  and  a  similar  discrepancy  was  common. 

Considering  that  these  were  trained  experts,  whose  special 
task  it  was,  in  this  case,  to  draw  the  corona,  which  therefore 
claimed  their  undivided  attention,  I  hardly  know  a  more  striking 
instance  of  the  fallibility  of  human  testimony.  The  evidence  of 
several  observers,  however,  pointed  to  the  fact  that  the  light 
really  was  more  nearly  confined  to  the  part  next  the  sun  than 
the  year  before,  so  that  the  corona  had  probably  changed  during 
that  interval,  and  grown  smaller,  which  was  remarkable  enough. 

The  evidence  of  the  polariscope,  on  the  whole,  showed  it  to  be 

4 


FIG.  37. —  ENLARGEMENT   OF   PART   OF  FIG. 


50  THE  NEW  ASTRONOMY. 

partly  due  to  reflected  sunlight,  while  the  spectroscope  in  the 
hands  of  Professor  Young  confirmed  the  last  year's  observation, 
that  it  was  also,  and  largely,  self-luminous.  Finally,  the  photo- 
graphs, taken  at  very  distant  stations,  showed  the  same  dark 
rifts  in  the  same  place,  and  thus  brought  confirmatory  evidence 
that  it  was  not  a  local  phenomenon  in  our  own  atmosphere. 
A  photograph  of  it,  taken  by  Mr.  Brothers  in  Sicily,  is  the 
subject  of  the  annexed  illustration  (Fig.  35),  in  which  the  very 
bright  lights  which,  owing  to  "photographic  irradiation,"  seem 
to  indent  the  moon,  are  chiefly  due  to  the  colored  flames  I  have 
spoken  of,  which  will  be  described  later. 

It  may  be  observed  that  the  photographs  taken  in  the  next 
year  (1871)  were  still  more  successful,  and  began  to  show  still 
more  of  the  structure,  whose  curious  forms,  resembling  large 
petals,  had  already  been  figured  by  Liais.  His  drawing  (Fig. 
36),  made  in  1857,  was  supposed  to  be  rather  a  fanciful  sketch 
than  a  trustworthy  one;  but,  as  it  will  be  seen,  the  photograph 
goes  far  to  justify  it. 

Figures  37  and  38  are  copies  published  by  Mr.  Ranyard  of 
the  excellent  photographs  obtained  in  1871,  which  are  perhaps 
as  good  as  anything  done  since,  though  even  these  do  not  show 
the  outer  corona.  The  first  is  an  enlargement  of  a  small  portion 
of  the  detail  in  the  second.  It  is  scarcely  possible  for  wood- 
engraving  to  reproduce  the  delicate  texture  of  the  original. 

The  years  brought  round  the  eclipse  of  1878,  which  was  again 
in  United  States  territory,  the  central  track  (as  Fig.  30  has  al- 
ready shown)  runninir  directly  over  one  of  the  loftiest  mountains 
of  the  country,  Pike's  Peak,  in  Colorado.  Pike's  Peak,  though 
over  fourteen  thousand  feet  high,  is  often  ascended  by  pleas- 
ure tourists ;  but  it  is  one  thing  to  stay  there  for  an  hour  or 
two,  and  another  to  take  up  one's  abode  there  and  get  accli- 
mated,—  for  to  do  the  latter  we  must  first  pass  through  the 
horrors  (not  too  strong  a  word)  of  mountain-sickness  This 


1  I 

1    -- 


THE  SUN'S  SURROUNDINGS.  53 

reaches  its  height  usually  on  the  second  or  third  day,  and  is 
something  like  violent  sea-sickness,  complicated  with  the  sensa- 
tions a  mouse  may  be  supposed  to  have  under  the  bell  of  an  air- 
pump.  After  a  week  the  strong  begin  to  get  over  it,  but  none 
but  the  very  robust  should  take  its  chances,  as  we  did,  without 
preparation ;  for  on  the  night  before  the  eclipse  the  life  of  one 
of  our  little  party  was  pronounced  in  danger,  and  he  was  carried 
down  in  a  litter  to  a  cabin  at  an  altitude  of  about  ten  thousand 
feet,  where  he  recovered  so  speedily  as  to  be  able  to  do  good  ser- 
vice on  the  following  day.  The  summit  of  the  "Peak"  is  cov- 
ered with  great  angular  bowlders  of  splintered  granite,  among 
which  we  laid  logs  brought  up  for  firewood,  and  on  these,  sacks 
of  damp  hay,  then  stretching  a  little  tent  over  all  and  tying  it 
down  with  wire  to  the  rocks,  we  were  fain  to  turn  in  under 
damp  blankets,  and  to  lie  awake  with  incessant  headache,  draw- 
ing long,  struggling  breaths  in  the  vain  attempt  to  get  air,  and 
wondering  how  long  the  tent  would  last,  as  the  canvas  flapped 
and  roared  with  a  noise  like  that  of  a  loose  sail  in  a  gale  at  sea, 
with  occasional  intervals  of  a  dead  silence,  usually  followed  by 
a  gust  that  shoved  against  the  tent  with  the  push  of  a  solid 
body,  and  if  a  sleeper's  shoulders  touched  the  canvas,  shoul- 
dered him  over  in  his  bed.  The  stout  canvas  held,  but  the 
snow  entered  with  the  wind  and  lay  in  a  deep  drift  on  the  pil- 
low, when  I  woke  after  a  brief  sleep  toward  morning,  and,  look- 
ing out  on  the  gray  dawn,  found  that  the  snow  had  turned  to 
hail,  which  was  rattling  sharply  on  the  rocks  with  an  accompa- 
niment of  thunder,  which  seemed  to  roll  from  all  parts  of  the 
horizon.  The  snow  lay  thick,  and  the  sheets  of  hail  were  like 
a  wall,  shutting  out  the  sight  of  everything  a  few  rods  off,  and 
this  was  in  July !  I  thought  of  my  December  station  in  sunny 
Andalusia. 

Hail,  rain,  sleet,  snow,  fog,  and  every  form  of  bad  weather 
continued  for  a  week  on  the  summit,  while  it  was  almost  always 


54 


THE  XEW  ASTRONOMY. 


clear  below.  It  was  often  a  remarkable  sight  to  go  to  the  edge 
and  look  down.  The  expanse  of  "the  plains,"  which  stretched 
eastward  to  a  horizon  line  over  a  hundred  miles  distant,  would 
be  in  bright  sunshine  beneath,  while  the  hail  was  all  around  and 
above  us ;  and  the  light  coming  up  instead  of  down  gave  sin- 


.  3J>.  —  "  SPECTRES." 


gular  effects  when  the  clouds  parted  below,  the  plains  seeming 
at  such  times  to  be  opalescent  with  luminous  yellow  and  green, 
as  though  the  lower  world  were  translucent,  and  the  sun  were 
beneath  it  and  shining  up  through.  Fig.  39  is  a  picture  of 
three  of  us  on  the  mountain-top,  who  s;nv  ji  rarer  spectacle; 
for  directly  opposite  the  setting  sun,  and  on  the  mist  over  the 


THE  SUN'S  SURROUNDINGS.  55 

gulf  beyond  us,  was  a  bright  ring,  in  whose  centre  were  three 
phantom  images  of  our  three  selves,  which  moved  as  we  moved, 
and  then  faded  as  the  sun  sank.  It  was  "the  spectre  of  the 
Brocken."  These  ghostly  presentments  were  tolerably  defined, 
as  in  the  sketch,  but  did  not  seem  to  be  gigantic,  as  some  have 
described  them.  We  rather  thought  them  close  at  hand ;  but 
before  we  could  determine,  the  vision  faded. 

The  clouds,  to  our  good  fortune,  rolled  away  on  the  29th ; 
and  a  number  of  pleasure-seekers,  who  came  up  to  view  the 
eclipse  and  the  unwonted  bright  sunshine,  made  a  scene  which 
it  was  hard  to  identify  with  the  usual  one.  This  time  my  busi- 
ness was  to  draw  the  corona;  and  the  extreme  altitude  and  the 
clearness  of  the  air,  with  perhaps  some  greater  extension  than 
usual  in  the  object  itself,  enabled  it  to  be  followed  to  an  unpre- 
cedented distance.  During  totality  the  sun  was  surrounded  by 
a  narrow  ring  —  hardly  more  than  a  line  —  of  vivid  light,  pre- 
senting no  structure  to  the  naked  eye  (but  a  remarkable  one  in 
the  telescope);  and  this  faded  with  great  suddenness  into  a  cir- 
cular nebulous  luminosity  between  two  and  three  diameters  of 
the  sun  wide,  but  without  such  marked  plumes,  or  filaments,  as 
I  had  seen  in  1869.  The  most  extraordinary  thing,  however, 
was  a  beam  of  light,  inclined  at  an  angle  of  about  forty-five 
degrees,  about  as  wide  as  the  sun,  and  extending  to  the  distance 
of  nearly  six  of  its  diameters  on  one  side  and  over  twelve  on  the 
other ;  on  one  side  alone,  that  is,  to  the  amazing  distance  of  over 
ten  million  miles  from  its  body.  Substantially  the  same  obser- 
vation was  made,  as  it  appeared  later,  by  Professor  Newcomb, 
at  a  lower  level.  The  direction,  when  more  carefully  measured, 
it  was  interesting  to  note,  coincided  closely  with  that  of  the 
Zodiacal  light,  and  a  faint  central  rib  added  to  its  resemblance 
to  that  body.  It  is  noteworthy,  in  illustration  of  what  has 
already  been  said  as  to  the  conflict  of  ocular  testimony,  that 
though  I,  with  the  great  majority  of  observers  below,  saw  only 


56  THE  NEW  ASTRONOMY. 

this  beam,  two  witnesses  whose  evidence  is  unimpeachable,  Pro- 
fessors Young  and  Abbe,  saw  a  pale  beam  at  right  angles  to  it ; 
and  that  one  observer  did  not  see  the  beam  in  question  at  all. 
Fig.  40  is  a  sketch  made  from  my  own,  but  necessarily  on  a 
scale  which  can  show  only  its  general  features. 

With  the  telescope,  the  whole  of  the  bright  inner  light  close 
to  the  sun  was  found  to  be  made  up  of  filaments,  more  definite 
even  than  those  described  in  a  previous  chapter  as  seen  in  sun- 
spots,  and  bristling  in  all  directions  from  the  edge ;  not  conceal- 
ing each  other,  as  we  might  expect  such  things  to  do,  upon  a 
sphere,  but  fringing  the  sun's  edge  in  definite  outline,  as  though 
it  were  .really  but  a  disk. 

Those  who  were  at  leisure  to  watch  the  coming  shadow  of 
the  moon  described  its  curved  outline  as  distinctly  visible  on 
the  plains.  "  A  rounded  ball  of  darkness  with  an  orange-yellow 
border,"  one  called  it  Those,  again,  who  looked  down  on  the 
bright  clouds  below  say  the  shadow  was  preceded  by  a  yellow 
fringe,  casting  a  bright  light  over  the  clouds  and  passing  into 
orange,  pink,  rose-red,  and  dark-red,  in  about  twenty  seconds. 
This  beautiful  effect  was  noticed  by  nearly  all  the  amateur 
observers  present,  who  had  their  attention  at  liberty,  and  was 
generally  unseen  by  the  professional  ones,  who  were  shut  up 
in  dark  tents  with  photometers,  or  engaged  otherwise  than  in 
admiring  the  glory  of  the  spectacle  as  a  spectacle  merely.  This 
strange  light,  forming  a  band  of  color  about  the  shadow  as  seen 
from  above,  must  have  really  covered  ten  miles  or  more  in 
width,  and  have  occupied  a  considerable  fraction  of  a  minute 
in  passing  over  the  heads  of  those  below,  to  whom  it  probably 
constituted  that  lurid  light  on  their  landscape  I  have  spoken 
of  as  so  peculiar  and  "unnatural."  It  seems  to  be  due  to  the 
colored  flames  round  the  sun,  which  shine  out  when  its  brighter 
light  is  extinguished.  I  should  add  that  on  the  summit  of  Pike's 
Peak  the  corona  did  not  entirely  disappear  at  the  instant  the  sun 


THK  SUN'S  SURROUNDINGS. 


59 


FIG.  41.  —  SPECTROSCOPE  SLIT 
AND  SOLAR  IMAGE.  (FROM 
"THE  SUN,"  BY  YOUNG.) 


broke  forth  again,  but  that  its  outlying  portions  first  went  and 
then  its  brighter  and  inner  ones,  till  our  eager  gaze,  trying  to 
follow  it  as  long  as  possible,  only  after  the 
lapse  of  some  minutes  saw  the  last  of  the 
wonderful  thing  disappear  and  "fade  into 
the  light  of  common  day." 

There  have  been  other  eclipses  since ; 
but,  in  spite  of  all,  our  knowledge  of  the 
corona  remains  very  incomplete,  and  if  the 
most  learned  in  such  matters  were  asked 
what  it  was,  he  could  probably  answer  truthfully,  "  I  don't 
know." 

This  will  not  be  wondered  at  when  it  is  considered  that  as 
total  eclipses  come,  about  every  other  year,  and  continue,  one 
with  another,  hardly  three  minutes,  an  astronomer  who  should 

devote  thirty  years  exclusively 
to  the  subject,  never  missing  an 
eclipse  in  whatever  quarter  of 
the  globe  it  occurred,  would  in 
that  time  have  secured,  in  all, 
something  like  three-quarters  of 
an  hour  for  observation.  Ac- 
cordingly, what  we  know  best 
about  the  corona  is  how  it  looks, 
what  it  is  being  still  largely 
conjecture ;  and  it  is  for  this 
reason  that  I  have  thought  the 
space  devoted  to  it  would  be  best  used  by  giving  the  unscien- 
tific reader  some  idea  of  the  visible  phenomena  as  they  present 
themselves  to  an  eyewitness.  Treatises  like  Lockyer's  "  Solar 
Physics,"  Proctor's  "  The  Sun,"  Secchi's  "  Le  Soleil,"  and  Young's 
"The  Sun"  (the  latter  is  most  recent),  will  give  the  reader  who 
desires  to  learn  more  of  the  little  that  is  known,  the  fuller  infor- 


FIG.    4'2.  —  SLIT    AND   PROMINENCES. 

("THE  SUN,"  BY  YOUNG.) 


60  THE  NEW  ASTRONOMY. 

mation  which  this  is  not  the  place  for ;  but  it  may  be  said  very 
briefly  that  it  is  certain  that  the  corona  is  at  times  of  enormous 
extent  (the  whole  length  of  the  longer  beam  seen  on  Pike's  Peak 
must  have  been  over  fourteen  million  miles),  that  it  almost  cer- 
tainly changes  in  its  shape  and  dimensions  from  year  to  year 
(possibly  much  oftener,  but  this  we  cannot  yet  know),  and  that 
it  shines  partly  by  its  own  and  partly  by  reflected  light.  When 
we  come  to  ask  whether  it  is  a  gas  or  not,  the  evidence  is  con- 
flicting. The  appearance  of  the  green  coronal  line,  and  other 
testimony  we  have  not  alluded  to,  would  make  it  seem  almost 
certain  that  there  must  be  a  gas  here  of  extreme  tenuity,  reach- 
ing the  height  of  some  hundred  thousand  miles,  at  the  least; 
while  yet  the  fact  that  such  light  bodies  as  comets  have  been 
known  to  pass  through  it,  close  to  the  sun,  without  suffering  any 
visible  retardation,  such  as  would  come  even  from  a  gas  far 
lighter  than  hydrogen,  appears  to  throw  doubt  on  evidence 
otherwise  strong.  It  is  possible  to  conceive  of  the  corona,  and 
especially  of  the  outer  portion,  as  very  largely  made  up  of 
minute  particles  such  as  form  the  scattered  dust  of  meteoric 
trains,  and  this  seems  to  be  the  most  probable  constitution  of  its 
outlying  parts.  It  is  even  possible  to  conceive  that  it  is  in  some 
degree  a  subjective  phenomenon,  caused,  as  Professor  Hastings 
has  suggested,  by  diffraction  upon  the  edge  of  the  moon,  —  the 
moon,  that  is,  not  merely  serving  as  a  screen  to  the  sun  to  reveal 
the  corona,  but  partly  making  the  corona  by  diffracting  the  light, 
somewhat  as  we  see  that  the  edge  of  any  very  distant  object 
screening  the  sun  is  gilded  by  its  beams.  This  effect  may  be 
seen  when  the  sun  rises  or  sets  unusually  clear,  for  objects  on 
the  horizon  partly  hiding  it  are  then  fringed  for  a  moment  with 
a  line  of  light,  —  an  appearance  which  has  not  escaped  Shaks- 
peare,  where  he  says, — 

"  But  when  from  under  this  terrestrial  ball 
He  fires  the  tall  tops  of  the  eastern  pines." 


THE  SUN'S  SURROUNDINGS.  61 

Still,  in  admitting  the  possibility  of  some  such  contributory 
effect  on  the  part  of  the  moon,  we  must  not,  of  course,  be  under- 
stood as  meaning  that  the  corona  as  a  whole  does  not  have  a 
real  existence,  quite  independent  of  the  changes  which  the  pres- 
ence of  the  moon  may  bring;  and  in  leaving  the  wonderful 
thing  we  must  remember  that  it  is,  after  all,  a  reality,  and  not 
a  phantasm. 

I  have  already  described  how,  at  the  eclipse  of  1870,  I  (with 
others)  saw  within  the  corona  what  seemed  like  rose  and  scarlet- 
colored  mountains  rising  from  the  sun's  edge,  an  appearance 
which  had  first  been  particularly  studied  in  the  eclipse  of  1868, 
two  years  before,  and  which,  it  might  be  added,  Messrs.  Lockyer 
and  Janssen  had  succeeded  in  observing  without  an  eclipse  by 
the  spectroscope.  Besides  the  corona,  it  may  be  said,  then,  that 
the  sun  is  surrounded  by  a  thin  envelope,  rising  here  and  there 
into  prominences  of  a  rose  and  scarlet  color,  invisible  in  the  tele- 
scope, except  at  a  total  eclipse,  but  always  visible  through  the 
spectroscope.  It  is  within  and  quite  distinct  from  the  corona, 
and  is  usually  called  the  "  chromosphere,"  being  a  sort  of  sphere 
of  colored  fire  surrounding  the  sun,  but  which  we  can  usually 
see  only  on  the  edge.  "  The  appearance,"  says  Young,  "is  as 
if  countless  jets  of  heated  gas  were  issuing  through  vents  and 
spiracles  over  the  whole  surface,  thus  clothing  it  with  flame, 
which  heaves  and  tosses  like  the  blaze  of  a  conflagration."  Out 
of  this,  then,  somewhat  like  greater  waves  or  larger  swellings  of 
the  colored  fires,  rise  the  prominences,  whose  place,  close  to  the 
sun's  edge,  has  been  indicated  in  many  of  the  drawings  and 
photographs  just  given  of  the  corona,  on  whose  background  they 
are  seen  during  eclipses ;  but  as  they  can  be  studied  at  our 
leisure  with  the  spectroscope,  we  have  reserved  a  more  particular 
description  of  them  till  now.  They  are  at  all  times  directly  be- 
fore us,  as  well  as  the  corona ;  but  while  both  are  yet  invisible 
from  the  overpowering  brightness  of  the  sunlight  reflected  from 


THE  NEW  ASTRONOMY. 


the  earth's  atmosphere  in  front  of  them,  these  red  flames  are  so- 
far  brighter  than  the  coronal  background,  that  if  we  could  only 
weaken  this  "glare"  a  little,  they  at  least  might  become  visible, 


even  if  the  corona  were  not.  The  difficulty  is  evidently  to  find 
some  contrivance  which  will  weaken  the  "glare"  without  en- 
feebling the  prominences  too ;  and  this  the  spectroscope  does  by 
diffusing  the  white  sunlight,  while  it  lets  the  color  pass  nearly 
unimpaired.  For  the  full  understanding  of  its  action -the  reader 


THE  SUN'S  SURROUNDINGS.  63 

must  be  referred  to  such  works  as  those  on  the  sun  already  men- 
tioned ;  but  a  general  idea  of  it  may  be  gathered,  if  we  reflect 
that  white  light  is  composed  of  every  possible  variety  of  colors, 
and  that  the  spectroscope,  which  consists  essentially  of  a  prism 
behind  a  very  narrow  slit  through  which  the  light  enters,  lets 
any  single  color  pass  freely,  without  weakening  it  or  altering  it 
in  anything  but  its  direction,  but  gives  a  different  direction  to 
each,  and  hence  sorts  out  the  tints,  distributing  them  side  by 
side,  every  one  in  its  own  place,  upon  the  long  colored  band 
called  the  spectrum.  If  this  distribution  has  spread  the  colors 
along  a  space  a  thousand  times  as  wide  as  the  original  beam,  the 
average  light  must  be  just  so  much  weaker  than  the  white  light 
was,  because  this  originally  consisted  of  a  thousand  (let  us  say  a 
thousand,  but  it  is  really  an  infinite  number)  mingled  tints  of 
blue,  green,  yellow,  orange,  and  red,  which  have  now  been  thus 
distributed.  If,  however,  we  look  through  the  prism  at  a  rose- 
leaf,  and  it  has  no  blue,  green,  yellow,  or  orange  in  it,  and 
nothing  but  pure  red,  as  each  single  color  passes  unchanged, 
this  red  will,  according  to  what  has  been  said,  be  as  bright  after 
it  has  passed  as  before.  All  depends,  then,  on  the  fact  that  these 
prominences  do  consist  mainly  of  light  of  one  color,  like  the 
rose-leaf,  so  that  this  monochromatic  light  will  be  seen  through 
the  spectroscope  just  as  it  is,  while  the  luminous  veil  of  glaring 
white  before  it  will  seem  to  be  brushed  away. 

If  a  large  telescope  be  directed  toward  the  sun,  the  glass  at 
the  farther  end  will,  if  we  remove  the  eye-piece,  form  a  little 
picture  of  the  sun,  as  a  picture  is  formed  in  a  camera-obscura ; 
and  now,  if  we  also  fasten  the  spectroscope  to  this  eye-end,  where 
the  observer's  head  would  be  were  he  looking  through,  the  edge 
of  the  solar  image  may  be  made  to  fall  just  off  the  slit,  so  that 
only  the  light  from  the  prominences  (and  the  white  glare  about 
them)  shall  pass  in.  To  see  this  more  clearly,  let  us  turn  our 
backs  to  the.  sun  and  the  telescope,  and  look  at  the  place  where 


64  THE  NEW  ASTRONOMY. 

the  image  falls  by  the  spectroscope  slit,  which  in  Fig.  41  is 
drawn  of  its  full  size.  This  is  a  brass  plate,  having  a  minute 
rectangular  window,  the  "  slit,"  in  it.  The  width  of  this  slit  is 
regulated  by  a  screw,  and  any  rays  falling  into  the  narrow  aper- 
ture pass  tln-ough  the  prism  within,  and  finally  fall  on  the  ob- 
server's eye,  but  not  till  they  have  been  sorted  by  the  prism  in 
the  manner  described.  Formed  on  the  brass  plate,  just  as  it 


FIG.  45.  —  VOGKL'S  CHROMOSPHERIC  FORMS.     ("BEOBACHTUNGEN,"  DR.  H.  c.  VOGEL.) 

would  be  formed  on  a  sheet  of  paper,  or  anything  else  held  in 
the  focus,  we  see  the  bright  solar  image,  a  circle  of  light  perhaps 
an  inch  and  a  half  in  diameter,  —  a  miniature  of  the  sun  with  its 
spots.  The  whole  of  the  sun  (the  photosphere)  then  is  hidden 
to  an  observer  who  is  looking  up  through  the  slit  from  the  other 
side,  for,  as  the  sun's  edge  does  not  quite  touch  the  slit,  none  of 
its  rays  can  enter  it ;  but  if  there  be  also  the  image  here  of  a 
prominence,  projecting  beyond  the  edge,  and  really  overhanging 
the  slit  (though  to  us  invisible  on  account  of  the  glare  about  it), 
these  rays  will  fall  into  the  slit  and  pass  down  to  the  prism, 
which  will  dispose  of  it  in  the  way  already  stated* 

And  now  let  us  get  to  the  other  side,  and,  looking  up  through 
the  prism  with  the  aid  of  a  magnify  ing-glass,  see  what  it  has 


THE  SUN'S  SURROUNDINGS.  65 

done  for  us  (Fig.  42).  The  large  rectangular  opening  here  is 
the  same  as  the  small  one  which  was  visible  from  the  outside, 
only  that  it  is  now  magnified,  and  what  was  before  invisible  is 
seen ;  the  edge  of  the  sun  itself  is  just  hidden,  but  the  scarlet 
flames  of  the  chromosphere  have  become  visible,  with  a  cloudy 
prominence  rising  above  them.  The  " flames"  are  flame-like 
only  in  form,  for  their  light  is  probably  due  not  to  any  combus- 
tion, but  to  the  glow  of  intensely  heated  matter ;  and  as  its  light 
is  not  quite  pure  red,  we  can,  by  going  to  another  part  of  the 
spectrum,  see  the  same  thing  repeated  in  orange,  the  effect  being 
as  though  we  had  a  number  of  long  narrow  windows,  some 
glazed  with  red,  some  with  orange,  and  some  with  other  colors, 
through  which  we  could  look  out  at  the  same  clouds.  I  have 
looked  at  these  prominences  often  in  this  way ;  but  I  prefer,  in 
the  reader's  interest,  to  borrow  from  the  description  by  Pro- 
fessor Young,  who  has  made  these  most  interesting  and  won- 
derful forms  a  special  study. 

Let  us  premise  that  the  depth  of  the  crimson  shell  out  of 
which  they  rise  is  usually  less  than  five  thousand  miles,  and 
that  though  the  prominences  vary  greatly,  the  majority  reach 
a  height  of  nearly  twenty  thousand  miles,  while  in  exceptional 
cases  this  is  immensely  exceeded.  Professor  Young  has  seen 
one  which  grew  to  a  height  of  three  hundred  and  fifty  thousand 
miles  in  an  hour  and  a  half,  and  in  half  an  hour  more  had  faded 
away. 

These  forms  fall  into  two  main  classes,  —  that  of  the  quiet  and 
cloud-like,  and  that  of  the  eruptive,  —  the  first  being  almost  ex- 
actly in  form  like  the  clouds  of  our  own  sky,  sometimes  appear- 
ing to  lie  on  the  limb  of  the  sun  like  a  bank  of  clouds  on  the 
horizon,  sometimes  floating  entirely  free  ;  while  sometimes  "  the 
whole  under  surface  is  fringed  with  down-hanging  filaments, 
which  remind  one  of  a  summer  shower  hanging  from  a  heavy 

thunder-cloud." 

5 


66  THE  NEW  ASTRONOMY. 

Here  are  some  of  the  typical  forms  of  the  quieter  ones  :  - 
Fig.  43,  by  Tacchini,  the  Director  of  the  Roman  Observa- 
tory, represents  an  ordinary  prominence,  or  cloud-group  in  the 
chromosphere,  whose  height  is  about  twenty-five  thousand  miles. 
The  little  spires  of  flame  which  rise,  thick  as  grass-blades,  every- 
where from  the  surface,  are  seen  on  its  right  and  left. 


FIG.    46.  —  TACCHINl'S   CHROMOSPHERIC    FORMS.       ("MEMORIE   DEGLI    8PETTROSCOPISTI 

ITALIANI.") 


Fig.  44  (Tacchini)  is  one  where  the  agitation  is  greater  and 
the  "filamentary"  type  is  more  marked.  Besides  the  curiously 
threadlike  forms  (so  suggestive  of  what  we  have  already  seen 
in  the  photosphere),  we  have  here  what  looks  like  an  extended 
cloudy  mass,  drawn  out  by  a  horizontally  moving  wind. 

Fig.  45  (by  Vogel,  at  Bothkamp)  represents  another  of  these 
numerous  types. 

The  extraordinary  Fig.  46  is  from  another  drawing,  by  Tac- 
chini, of  a  protuberance  seen  in  187L  (a  time  of  great  solar 
disturbance),  and  it  belongs  to  the  more  energetic  of  its  class. 


THE  SUN'S  SURROUNDINGS. 


67 


FIG.    47.  —  ERUPTIVE    PROMINENCES.       ("THE    SUN,"   BY   YOUNG.) 

Tin's  fantastic  cloud-shape,  "  if  shape  it  might  be  called  that 
shape  had  none,"  looking  like  some  nightmare  vision,  was  about 
fifty  thousand  miles  long  and  sixty  thousand  high  above  the 
surface.  The  reader  will  notice  also  the  fiery  rain,  like  the 
drops  from  a  falling  rocket,  and  may  add  to  it  all,  in  imagi- 
nation, the  actual  color,  which  is  of  a  deep  scarlet. 

It  may  add  to  the -interest  such*  things  excite,  to  know  that 
they  have  some  mysterjous  connection  with  a  terrestrial  phe- 
nomenon, —  the  aurora,  —  for  the  northern  lights  have  been 


68  THE  NEW  ASTRONOMY. 

again  and  again  noticed  to  dance  in  company  with  these  solar 
displays. 

The  eruptive  prominences  are  very  different  in  appearance, 
as  will  be  seen  by  the  next  illustration,  for  which  we  are  in- 
debted to  Professor  Young. 

In  Fig.  47  we  have  a  group  of  most  interesting  views  by  him 
(drawn  here  on  the  common  scale  of  seventy-five  thousand  miles 
to  an  inch),  illustrating  the  more  eruptive  types,  of  which  we 
will  let  him  speak  directly.  The  first  shows  a  case  of  the  ver- 
tical filaments,  like  those  rocket-drops  we  saw  just  now  in  Tac- 
chini's  drawing,  but  here  more  marked;  while  the  second  (on 
the  left  side)  is  a  cyclone-form,  where  the  twisted  stems  sug- 
gest what  we  have  seen  before  in  the  "bridges"  of  sun-spots, 
and  below  this  is  another  example  of  filamentary  forms. 

The  upper  one,  on  the  right,  is  the  view  of  a  cloud  promi- 
nence as  it  appeared  at  half-past  twelve  o'clock,  on  Sept.  7, 
1871.  Below  it  is  the  same  prominence  at  one  o'clock  (half  an 
hour  later),  when  it  has  been  shattered  by  some  inconceivable 
explosion,  blowing  it  into  fragments,  and  driving  the  hydrogen 
to  a  height  of  two  hundred  thousand  miles.  The  lowest  figure 
on  the  right  shows  another  case  where  inclined  jets  (of  hydro- 
gen) were  seen  to  rise  to  a  height  of  fifty  thousand  miles. 

Professor  Young  says  of  these :  — 

"  Their  form  and  appearance  change  with  great  rapidity,  so  that  the 
motion  can  almost  be  seen  with  the  eye.  Sometimes  they  consist  of 
pointed  rays,  diverging  in  all  directions,  like  hedgehog-spines.  Some- 
times they  look  like  flames ;  sometimes  like  sheaves  of  grain  ;  sometimes 
like  whirling  water-spouts,  capped  with  a  great  cloud ;  occasionally  they 
present  most  exactly  the  appearance  of  jets  of  liquid  fire,  rising  and  fall- 
ing in  graceful  parabolas ;  frequently  they  carry  on  their  edges  spirals 
like  the  volutes  of  an  Ionic  column ;  and  continually  they  detach  fila- 
ments which  rise  to  a  great  elevation,  gradually  expanding  and  growing 
fainter  as  they  ascend,  until  the  eye  loses  them.  There  is  no  end  to  the 
number  of  curious  and  interesting  appearances  which  they  exhibit  under 


THE  SUN'S  SURROUNDINGS.  69 

varying  circumstances.  The  velocity  of  the  motions  often  exceeds  a 
hundred  miles  a  second,  and  sometimes,  though  very  rarely,  reaches 
two  hundred  miles." 

In  the  case  of  the  particular  phenomenon  recorded  by  Pro- 
fessor Young  in  the  last  illustration,  Mr.  Proctor,  however,  has 
calculated  that  the  initial  velocity  probably  exceeded  five  hun- 
dred miles  a  second,  which,  except  for  the  resistance  experienced 
by  the  sun's  own  atmosphere,  would  have  hurled  the  ejected 
matter  into  space  entirely  clear  of  the  sun's  power  to  recall  it, 
so  that  it  would  never  return. 

It  adds  to  our  interest  in  these  flames  to  know  that  they  at 
least  are  connected  with  that  up-rush  of  heated  matter  from  the 
sun's  interior,  forming  a  part  of  the  circulation  which  maintains 
both  the  temperature  of  its  surface  and  that  radiation  on  which 
all  terrestrial  life  depends.  The  flames,  indeed,  add  of  them- 
selves little  to  the  heat  the  sun  sends  us,  but  they  are  in  this 
way  the  outward  and  visible  signs  of  a  constant  process  writhin, 
by  which  we  live ;  and  so  far  they  seem  to  have  a  more  imme- 
diate interest  to  us,  though  invisible,  than  the  corona  which  sur- 
rounds them.  But  we  must  remember  when  we  lift  our  eyes  to 
the  sun  that  this  latter  wonder  is  really  there,  whether  man  sees 
it  or  not,  and  that  the  cause  of  its  existence  is  still  unknown. 

We  ask  for  its  " object"  perhaps  with  an  unconscious  assump-~~T 
tion  that  the  whole  must  have  been  in  some  way  provided  to 
subserve  our  wants ;  but  there  is  not  as  yet  the  slightest  evidence 
connecting  its  existence  with  any  human  need  or  purpose,  and 
as  yet  we  have  no  knowledge  that,  in  this  sense,  it  exists  to  any 
"end"  at  all.  "As  the  thought  of  man  is  widened  with  the 
process  of  the  suns,"  let  us  hope  that  we  shall  one  day 
more. 


TIT. 

THE   SUN'S   ENERGY. 

"  TT  is  indeed,"  says  good  Bishop  Berkeley,  "an  opinion 
JL  strangely  prevailing  amongst  men  that  ...  all  sensible 
objects  have  an  existence  .  .  .  distinct  from  their  being  per- 
ceived by  the  understanding.  But  .  .  .  some  truths  there  are, 
so  near  and  obvious  to  the  mind,  that  a  man  need  only  open 
his  eyes  to  see  them.  Such  I  take  this  important  one  to  be, 
namely,  that  all  the  choir  of  heaven  and  furniture  of  the  earth  — 
in  a  word,  all  those  bodies  which  compose  the  mighty  frame  of 
the  world  —  have  not  any  subsistence  without  a  mind." 

We  are  not  going  to  take  the  reader  along  "  the  high  priori 
road"  of  metaphysics,  but  only  to  speak  of  certain  accepted 
conclusions  of  modern  experimental  physics,  which  do  not  them- 
selves, indeed,  justify  all  of  Berkeley's  language,  but  to  which 
these  words  of  the  author  of  "  A  New  Theory  of  Vision  "  seem 
to  be  a  not  unfit  prelude. 

When  we  see  a  rose-leaf,  we  see  with  it  what  we  call  a  color, 
and  we  Miv  ?ipt  to  think  it  is  in  the  rose.  But  the  color  is  in  ust 
for  it  is  a  sensation  which  something  coming  from  the  sun  ex- 
cites in  the  eye ;  so  that  if  the  rose-leaf  were  still  there,  there 
would  be  no  color  unless  there  were  an  eye  to  receive  and  a 
brain  to  interpret  the  sensation.  Every  color  that  is  lovely  in 
the  rainbow  or  the  flower,  every  hue  that  is  vivid  in  a  ribbon  or 
sombre  in  the  grave  harmonies  of  some  old  Persian  rug,  the 
metallic  lustre  of  the  humming-bird  or  the  sober  imperial  yellow 


THE  SUN'S  ENERGY.  71 

of  precious  china,  —  all  these  have  no  existence  as  color  apart 
from  the  seeing  eye,  and  all  have  their  fount  and  origin  in  the 
sun  itself. 

"Color"  and  "light,"  then,  are  not,  properly  speaking,  exter- 
nal things,  but  names  given  to  the  sensations  caused  by  an 
uncomprehended  something  radiated  from  the  sun,  when  this 
falls  on  our  eyes.  If  this  very  same  something  falls  on  our  face, 
it  produces  another  kind  of  sensation,  which  we  call  "heat,"  or 
if  it  falls  on  a  thermometer  it  makes  it  rise ;  while  if  it  rests  long 
on  the  face  it  will  produce  yet  another  effect,  "  chemical  action," 
for  it  will  tan  the  cheek,  producing  a  chemical  change  there ; 
or  it  will  do  the  like  work  more  promptly  if  it  meet  a  photo- 
graphic plate.  If  we  bear  in  mind  that  it  is  the  identically  same 
thing  (whatever  that  is)  which  produces  all  these  diverse  effects, 
we  see,  some  of  us  perhaps  for  the  first  time,  that  "  color," 
"light,"  "radiant  heat,"  "actinism,"  etc.,  are  only  names  given 
to  the  diverse  effects  of  some  thing,  not  things  themselves ;  so 
that,  for  instance,  all  the  splendor  of  color  in  the  visible  world 
exists  only  in  the  eye  that  sees  it.  The  reader  must  not  suppose 
that  he  is  here  being  asked  to  entertain  any  metaphysical  sub- 
tlety. We  are  considering  a  fact  almost  universally  accepted 
within  the  last  few  years  by  physicists,  who  now  generally 
admit  the  existence  of  a  something  coining  from  the  sun,  which 
is  not  itself  light,  heat,  or  chemical  action,  but  of  which  these 
are  effects.  When  we  give  this  unknown  thing  a  name,  we  call 
it  "  radiant  energy." 

How  it  crosses  the  void  of  space  we  cannot  be  properly  said 
to  know,  but  all  the  phenomena  lead  us  to  think  it  is  in  the 
form  of  motion  in  some  medium,  —  somewhat  (to  use  an  imper- 
fect analogy)  like  the  transmission  through  the  air  of  the  vibra- 
tions which  will  cause  sound  when  they  reach  an  ear.  This,  at 
any  rate,  is  certain,  that  there  is  an  action  of  some  sort  inces- 
santly going  on  between  us  and  the  sun,  which  enables  us  to 


72  THE  NEW  ASTRONOMY. 

experience  the  effects  of  light  and  heat.  We  assume  it  to  be  a 
particular  mode  of  vibration ;  but  whatever  it  is,  it  is  repeated 
with  incomprehensible  rapidity.  Experiments  recently  made  by 
the  writer  show  that  the  slower  heat  vibrations  which  reach  us 
from  the  sun  succeed  each  other  nearly  100,000,000,000,000 
times  in  a  single  second,  while  those  which  make  us  see,  have 
long  been  known  to  be  more  rapid  still.  These  pass  outward 
from  the  sun  in  every  direction,  in  ever- widening  spheres ;  and 
in  them,  so  far  as  we  know,  lies  the  potency  of  life  for  the 
planet  upon  whose  surface  they  fall. 

Did  the  reader  ever  consider  that  next  to  the  mystery  of 
gravitation,  which  draws  all  things  on  the  earth's  surface  down, 
comes  that  mystery  —  not  seen  to  be  one  because  so  familiar  — 
of  the  occult  force  in  the  sunbeams  which  lifts  tilings  up  f  The 
incomprehensible  energy  of  the  sunbeam  brought  the  carbon  out 
of  the  air,  put  it  together  in  the  weed  or  the  plant,  and  lifted 
each  tree-trunk  above  the  soil.  The  soil  did  not  lift  it,  any 
more  than  the  soil  in  Broadway  lifted  the  spire  of  Trinity.  Men 
brought  stones  there  in  wagons  to  build  the  church,  and  the  sun 
brought  the  materials  in  its  own  way,  and  built  up  alike  the 
slender  shaft  that  sustains  the  grass  blade  and  the  column  of 
the  pine.  If  the  tree  or  the  spire  fell,  it  would  require  a  certain 
amount  of  work  of  men  or  horses  or  engines  to  set  it  up  again. 
So  much  actual  work,  at  least,  the  sun  did  in  the  original  build- 
ing ;  and  if  we  consider  the  number  of  trees  in  the  forest,  we  see 
that  this  alone  is  something  great.  But  besides  this,  the  sun 
locked  up  in  each  tree  a  store  of  energy  thousands  of  times 
greater  than  that  which  was  spent  in  merely  lifting  the  trunk 
from  the  ground,  as  we  may  see  by  unlocking  it  again,  when  we 
burn  the  tree  under  the  boiler  of  an  engine ;  for  it  will  develop 
a  power  equal  to  the  lifting  of  thousands  of  its  kind,  if  we 
choose  to  employ  it  in  this  way.  This  is  so  true,  that  the  tree 
may  fall,  and  turn  to  coal  in  the  soil,  and  still  keep  this  energy 


TIIK  SUN'S  ENERGY.  73 

imprisoned  in  it,  —  keep  it  for  millions  of  years,  till  the  black 
lump  under  the  furnace  gives  out,  in  the  whirling  spindles  of 
the  factory  or  the  turning  wheel  of  the  steamboat,  the  energy 
gathered  in  the  sunshine  of  the  primeval  world. 

The  most  active  rays  in  building  up  plant-life  are  said  to  be 
the  yellow  and  orange,  though  Nature's  fondness  for  green 
everywhere  is  probably  justified  by  some  special  utility.  At 
any  rate,  the  action  of  these  solar  rays  is  to  decompose  the 
products  of  combustion,  to  set  free  the  oxygen,  and  to  fix  the 
carbon  in  the  plant.  Perhaps  these  words  do  not  convey  a 
definite  meaning  to  the  reader,  but  it  is  to  be  hoped  they  will, 
for  the  statement  they  imply  is  wonderful  enough.  Swift's 
philosopher  at  Laputa,  who  had  a  project  for  extracting  sun- 
beams out  of  cucumbers,  was  wiser  than  his  author  knew ;  for 
cucumbers,  like  other  vegetables,  are  now  found  to  be  really  in 
large  part  put  together  by  sunbeams,  and  sunbeams,  or  what  is 
scarcely  distinguishable  from  such,  could  with  our  present  scien- 
tific knowledge  be  extracted  from  cucumbers  again,  only  the 
process  would  be  too  expensive  to  pay.  The  sunbeam,  how- 
ever, does  what  our  wisest  chemistry  cannot  do :  it  takes  the 
burned  out  ashes  and  makes  them  anew  into  green  wood ;  it 
takes  the  close  and  breathed  out  air,  and  makes  it  sweet  and  fit 
to  breathe  by  means  of  the  plant,  whose  food  is  the  same  as  our 
poison.  With  the  aid  of  sunlight  a  lily  would  thrive  on  the 
deadly  atmosphere  of  the  " black  hole  of  Calcutta;"  for  this 
bane  to  us,  we  repeat,  is  vital  air  to  the  plant,  which  breathes 
it  in  through  all  its  pores,  bringing  it  into  contact  with  the  chlo- 
rophyl,  its  green  blood,  which  is  to  it  what  the  red  blood  is  to 
us ;  doing  almost  everything,  however,  by  means  of  the  sun 
ray,  for  if  this  be  lacking,  the  oxygen  is  no  longer  set  free  or 
the  carbon  retained,  and  the  plant  dies.  This  too  brief  state- 
ment must  answer  instead  of  a  fuller  description  of  how  the 
sun's  energy  builds  up  the  vegetable  world. 


74  THE  NEW  ASTRONOMY. 

But  the  ox,  the  sheep,  and  the  lamb  feed  on  the  vegetable, 
and  we  in  turn  on  them  (and  on  vegetables  too) ;  so  that, 
though  we  might  eat  our  own  meals  in  darkness  and  still  live, 
the  meals  themselves  are  provided  literally  at  the  sun's  expense, 
virtue  having  gone  out  of  him  to  furnish  each  morsel  we  put  in 
our  mouths.  But  while  he  thus  prepares  the  material  for  our 
own  bodies,  and  while  it  is  plain  that  without  him  we  could  not 
exist  any  more  than  the  plant,  the  processes  by  which  he  acts 
grow  more  intricate  and  more  obscure  in  our  own  higher  organ- 
ism, so  that  science  as  yet  only  half  guesses  how  the  sun  makes 
us.  But  the  making  is  done  in  some  way  by  the  sun,  and  so 
almost  exclusively  is  every  process  of  life. 

It  is  not  generally  understood,  I  think,  how  literally  true  this 
is  of  every  object  in  the  organic  world.  In  a  subsequent  illus- 
tration we  shall  see  a  newspaper  being  printed  by  power  directly 
and  visibly  derived  from  the  sunbeam.  But  all  the  power  de- 
rived from  coal,  and  all  the  power  derived  from  human  muscles, 
comes  originally  from  the  sun,  in  just  as  literal  a  sense ;  for  the 
paper  on  which  the  reader's  eye  rests  was  not  only  made  pri- 
marily from  material  grown  by  the  sun,  but  was  stitched  to- 
gether by  derived  sun-power,  and  by  this,  also,  each  page  was 
printed,  so  that  the  amount  of  this  solar  radiation  expended  for 
printing  each  chapter  of  this  book  could  be  stated  with  approxi- 
mate accuracy  in  figures.  To  make  even  the  reader's  hand 
which  holds  this  page,  or  the  eye  which  sees  it,  energy  again 
went  out  from  the  sun ;  and  in  saying  this  I  am  to  be  under- 
stood in  the  plain  and  common  meaning  of  the  words. 

Did  the  reader  ever  happen  to  be  in  a  great  cotton-mill, 
where  many  hundreds  of  operatives  watched  many  thousands 
of  spindles  ?  Nothing  is  visible  to  cause  the  multiplied  move- 
ment, the  engine  being  perhaps  away  in  altogether  another 
building.  Wandering  from  room  to  room,  where  everything  is 
in  motion  derived  from  some  unseen  source,  he  may  be  arrested 


THE  SUN'S  ENERGY.  75 

in  his  walk  by  a  sudden  cessation  of  the  lium  and  bustle,  —  at 
once  on  the  floor  below,  and  on  that  above,  and  all  around  him. 
The  simultaneousness  of  this  stoppage  at  points  far  apart  when 
the  steam  is  turned  off,  strikes  one  with  a  sense  of  the  intimate 
dependence  of  every  complex  process  going  on  upon  some  re- 
mote invisible  motor.  The  cessation  is  not,  however,  absolutely 
instantaneous ;  for  the  great  fly-wheel,  in  which  a  trifling  part  of 
the  motor  power  is  stored,  makes  one  or  two  turns  more,  till  the 
energy  in  this  also  is  exhausted,  and  all  is  still.  The  coal-beds 
and  the  forests  are  to  the  sun  what  the  flv- wheel  is  to  the 

w 

engine :  all  their  power  comes  from  him  ;  they  retain  a  little  of 
it  in  store,  but  very  little  by  comparison  with  the  original ;  and 
were  the  change  we  have  already  spoken  of  to  come  over  the 
sun's  circulation,  —  were  the  solar  engine  disconnected  from  us, 
—  we  could  go  on  perhaps  a  short  time  at  the  cost  of  this  store, 
but  when  this  was  over  it  would  be  over  with  us,  and  all  would 
be  still  here  too. 

Is  there  not  a  special  interest  for  us  in  that  New  Astronomy 
which  considers  these  things,  and  studies  the  sun,  not  only  in 
the  heavens  as  a  star,  but  in  its  workings  here,  and  so  largely 
in  its  relations  to  man  ? 

Since,  then,  we  are  the  children  of  the  sun,  and  our  bodies  a 
product  of  its  rays,  as  much  as  the  ephemeral  insects  that  its 
heat  hatches  from  the  soil,  it  is  a  worthy  problem  to  learn  how 
things  earthly  depend  upon  this  material  ruler  of  our  days.  But 
although  we  know  it  does  nearly  all  things  done  on  the  earth, 
and  have  learned  a  little  of  the  way  it  builds  up  the  plant,  we 
know  so  little  of  the  way  it  does  many  other  things  here  that 
we  are  still  often  only  able  to  connect  the  terrestrial  effect  with 
the  solar  cause  by  noting  what  events  happen  together.  We  are 
in  this  respect  in  the  position  of  our  forefathers,  who  had  not  yet 
learned  the  science  of  electricity,  but  who  noted  that  when  a 


• 


76  THE  NEW  ASTRONOMY. 

flash  of  lightning  came  a  clap  of  thunder  followed,  and  con- 
cluded as  justly  as  Franklin  or  Faraday  could  have  done  that 
there  was  a  physical  relation  between  them.  Quite  in  this  way, 
we  who  are  in  a  like  position  with  regard  to  the  New  Astron- 
omy, which  we  hope  will  one  day  explain  to  us  what  is  at 
present  mysterious  in  our  connection  with  the  sun,  can  as  yet 
often  only  infer  that  when  certain  phenomena  there  are  followed 
or  accompanied  by  others  here,  all  are  really  connected  as  prod- 
ucts of  one  cause,  however  dissimilar  they  may  look,  and  how- 
ever little  we  know  what  the  real  connection  may  be. 

There  is  no  more  common  inquiry  than  as  to  the  influence  of 
sun-spots  on  the  weather ;  but  as  we  do  not  yet  know  the  real 
nature  of  the  connection,  if  there  be  any,  we  can  only  try  to 
find  out  by  assembling  independent  records  of  sun-spots  and  of 
the  weather  here,  and  noticing  if  any  changes  in  the  one  are 
accompanied  by  changes  in  the  other ;  to  see,  for  instance,  if 
when  sun-spots  are  plenty  the  weather  the  world  over  is  rainy 
or  not,  or  to  see  if  when  an  unusual  disturbance  breaks  out  in 
a  sun-spot  any  terrestrial  disturbance  is  simultaneously  noted. 

When  we  remember  how  our  lives  depend  on  a  certain  circu- 
lation in  the  sun,  of  which  the  spots  appear  to  be  special  ex- 
amples, it  is  of  interest  not  only  to  study  the  forms  within  them, 
as  we  have  already  been  doing  here,  but  to  ask  whether  the 
spots  themselves  are  present  as  much  one  year  as  another.  The 
sun  sometimes  has  numerous  spots  on  it,  and  sometimes  none  at 
;ill ;  but  it  does  not  seem  to  have  occurred  to  any  one  to  see 
whether  they  had  any  regular  period  for  coming  or  going,  till 
Schwabe,  a  magistrate  in  a  little  German  town,  who  happened 
to  have  a  small  telescope  and  a  good  deal  of  leisure,  began  for 
his  own  amusement  to  note  their  number  every  day.  He  com- 
menced in  1826,  and  with  German  patience  observed  daily  for 
forty  years.  He  first  found  that  the  spots  grew  more  numerous 
in  1830,  when  there  was  no  single  day  without  one  ;  then  the 


THE  SUN'S  ENERGY. 


(  I 


number  declined  very  rapidly,  till  in  1833  they  were  about 
gone;  then  they  increased  in  number  again  till  1838,  then  again 
declined ;  and  so  on,  till  it  became  evident  that  sun-spots  do  not 
come  and  go  by  chance,  but  run  through  a  cycle  of  growth  and 
disappearance,  on  the  average  about  once  in  every  eleven  years. 
AVhile  amusing  himself  with  his  telescope,  an  important  sequence 


FIG.    48.  -*-  SUN-SPOT  8   AND   PRICE   OF   GRAIN.       (FROM    "OBSERVATIONS    OF    SOLAR   SPOTS.") 

in  Nature  had  thus  been  added  to  our  knowledge  by  the  obscure 
Hofrath  Schwabe,  who  indeed  compares  himself  to  Saul,  going 
out  to  seek  his  father's  asses  and  finding  a  kingdom.  Old  rec- 
ords made  before  Schwabe's  time  have  since  been  hunted  up,  so 
that  we  have  a  fairly  connected  history  of  the  sun's  surface  for 
nearly  a  hundred  and  fifty  years ;  and  the  years  when  spots  will 
be  plentiful  or  rare  can  now  be  often  predicted  from  seeing 


78  THE  NEW  ASTRONOMY. 

what  has  been  in  the  past.  Tims  I  may  venture  to  say  that  the 
spots,  so  frequent  in  1885,  will  have  probably  nearly  disappeared 
in  1888,  and  will  be  probably  very  plentiful  in  1894.  I  do  not 
know  at  all  why  this  is  likely  to  happen ;  I  only  know  that  it 
has  repeatedly  happened  at  corresponding  periods  in  the  past. 

"Now,"  it  may  be  asked,  "have  these  things  any  connection 
with  weather  changes,  and  is  it  of  any  practical  advantage  to 
know  if  they  have  I " 

Would  it  be,  it  may  be  answered,  of  any  practical  interest  to 
a  merchant  in  bread-stuffs  to  have  private  information  of  a  reli- 
able character  that  crops  the  world  over  would  be  fine  in  1888 
and  fail  in  1894 1  The  exclusive  possession  of  such  knowledge 
might  plainly  bring  "  wealth  beyond  the  dreams  of  avarice  "  to 
the  user;  or,  to  ascend  from  the  lower  ground  of  personal 
interest  to  the  higher  aims  of  philanthropy  and  science,  could 
we  predict  the  harvests,  we  should  be  armed  with  a  knowledge 
that  might  provide  against  coming  years  of  famine,  and  make 
life  distinctly  happier  and  easier  to  hundreds  of  millions  of 
toilers  on  the  earth's  surface. 

"But  can  we  predict?"  We  certainly  cannot  till  we  have, 
at  any  rate,  first  shown  that  there  is  a  connection  between  sun- 
spots  and  the  weather.  Since  we  know  nothing  of  the  ultimate 
causes  involved,  we  can  only  at  present,  as  I  say,  collect  records 
of  the  changes  there,  and  compare  them  with  others  of  the 
changes  here,  to  see  if  there  is  any  significant  coincidence. 
To  avoid  columns  of  figures,  and  yet  to  enable  the  reader 
to  judge  for  himself  in  some  degree  of  the  evidence,  I  will 
give  the  results  of  some  of  these  records  represented  graphi- 
cally by  curves,  like  those  which  he  may  perhaps  remember 
to  have  seen  used  to  show  the  fluctuations  in  the  value  of 
gold  and  grain,  or  of  stocks  in  the  stock-market.  It  is  only 
fair  to  say  that  mathematicians  used  this  method  long  before 
it  was  ever  heard  of  by  business  men,  and  that  the  stock- 


THE  SUN'S  ENERGY.  79 

brokers  borrowed  it  from  the  astronomers,  and  not  the  astrono- 
mers from  them. 

In  Fig.  48,  from  Carrington's  work,  each  horizontal  space 
represents  ten  years  of  time,  and  the  figures  in  the  upper  part 
represent  the  fluctuations  of  the  sun-spot  curve.  In  the  middle 
curve,  variations  in  vertical  distances  correspond  to  differences 
in  the  distance  from  the  sun  of  the  planet  Jupiter,  the  possibility 
of  whose  influence  on  sun-spot  periods  can  thus  be  examined. 
In  the  third  and  lowest,  suggested  by  Sir  William  Herschel,  the 
figures  at  the  side  are  proportional  to  the  price  of  wheat  in  the 
English  market,  rising  when  wheat  ruled  high,  falling  when  it 
was  cheap.  In  all  three  curves  one-tenth  of  a  horizontal  spacing 
along  the  top  or  bottom  corresponds  to  one  year;  and  in  this 
way  we  have  at  a  glance  the  condensed  result  of  observations 
and  statistics  for  sixty  years,  which  otherwise  stated  would  fill 
volumes.  The  result  is  instructive  in  more  ways  than  one. 
The  variations  of  Jupiter's  distance  certainly  do  present  a  strik- 
ing coincidence  with  the  changes  in  spot  frequency,  and  this 
may  indicate  a  real  connection  between  the  phenomena;  but 
before  we  decide  that  it  does  so,  we  must  remember  that  the 
number  of  cycles  of  change  presented  by  the  possible  combina- 
tion of  planetary  periods  is  all  but  infinite.  Thus  we  might 
safely  undertake,  with  study  enough,  to  find  a  curve,  depending 
solely  on  certain  planetary  configurations,  which  yet  would 
represent  with  quite  striking  agreement  for  a  time  the  rise  and 
fall  in  any  given  railroad  stock,  the  relative  numbers  of  Demo- 
cratic and  Eepublican  congressmen  from  year  to  year,  or  any- 
thing else  with  which  the  heavenly  bodies  have  in  reality  as 
little  to  do.  The  third  curve  (meant  by  the  price  of  wheat  to 
test  the  possible  influence  of  sun-spots  on  years  of  good  or  bad 
harvests)  is  not  open  to  the  last  objection,  but  involves  a  fallacy 
of  another  kind.  In  fact  the  price  of  wheat  depends  on  many 
things  quite  apart  from  the  operations  of  Nature,  —  on  wars  and 


80  THE  NEW  ASTRONOMY. 

legislation,  for  instance  ;  and  here  the  great  rise  in  the  first 
years  of  the  century  is  as  clearly  connected  with  the  great  con- 
tinental wars  of  the  first  Napoleon,  which  shut  up  foreign  ports, 
as  the  sudden  fall  about  1815,  the  year  of  Waterloo,  is  with  the 
subsequent  peace.  Meanwhile  an  immense  amount  of  labor  has 
been  spent  in  making  tables  of  the  weather,  and  of  almost  every 
conceivable  earthly  phenomenon  which  may  be  supposed  to 
have  a  similar  periodic  character,  with  very  doubtful  success, 
nearly  every  one  having  brought  out  some  result  which  might 
be  plausible  if  it  stood  alone,  but  which  is  apt  to  be  contradicted 
by  the  others.  For  instance,  Mr.  Stone,  at  the  Cape  of  Good 

Hope,  and  Dr.  Gould,  in 
South  America,  consider 
that  the  observations  taken 
at  those  places  show  a  lit- 
tle diminution  of  the  earth's 
temperature  (amounting  to 


riJijft  \  fW^*  one  or  two  degrees)  at  a 

V  sun-spot     maximum.      Mr. 

FIG.  49.—  SUN-SPOT  OF  NOV.  16,  isss,  AND  EARTH.       Chambers  concludes,  from 

twenty-eight  years'   obser- 

vations, that  the  hottest  are  those  of  most  sun-spots.  So  each  of 
these  contradicts  the  other.  Then  we  have  Grelinck,  who,  from 
a  study  of  numerous  observations,  concludes  that  all  are  wrong 
together,  and  that  there  is  really  no  change  in  either  way. 

I  might  go  on  citing  names  with  no  better  result.  One 
observer  tabulates  observations  of  terrestrial  temperature,  or 
rain-fall,  or  barometer,  or  ozone  ;  another,  the  visitations  of 
Asiatic  cholera  ;  while  still  another  (the  late  Professor  Jevons) 
tabulates  commercial  crises  with  the  serious  attempt  to  find  a 
connection  between  the  sun-spots  and  business  panics.  Of 
making  such  cycles  there  is  no  end,  and  much  study  of  them 
would  be  a  weariness  I  will  not  inflict. 


O  a  4  6  8  10  .  12  14  16  1ft  20  2£  24 


AjM40 J 


Jh 


FIG.    50. —  GREENWICH   RECORD   OF   DISTURBANCE   OF   MAGNETIC    NEEDLE,    NOV.    16   AND    17,  1882. 

6 


THE  SUN'S  ENERGY.  83 

Our  own  conclusion  is,  that  from  such  investigations  of 
terrestrial  changes  nothing  is  yet  certainly  known  with  regard 
to  the  influence  of  sun-spots  on  the  weather.  There  is,  however, 
quite  another  way ;  that  is,  to  measure  their  effect  at  the  origin 
in  the  sun  itself.  The  sun-spot  is  cooler  than  the  rest  of  the 
surface,  and  it  might  be  thought  that  when  there  are  many  the 
sun  would  give  less  heat.  As  far  as  the  spots  themselves  are 
concerned,  this  is  so,  but  in  a  very  small  degree.  I  have  been 
able  to  ascertain  how  much  this  deprivation  of  heat  amounts  to, 
and  find  it  is  a  real  but  a  most  insignificant  quantity,  rising  to 
about  two-thirds  of  one  degree  Fahrenheit  every  eleven  years. 
This,  it  will  be  remembered,  is  the  direct  effect  of  the  spots 
considered  merely  as  so  many  cool  patches  on  the  surface,  and 
it  does  not  imply  that  when  there  are  most  spots  the  sun  will 
necessarily  give  less  heat.  In  fact  there  may  be  a  compensating 
action  accompanying  them  which  makes  the  radiation  greater 
than  when  they  are  absent.  I  will  not  enter  on  a  detailed 
explanation,  but  only  say  that  in  the  best  judgment  I  can  form 
by  a  good  deal  of  study  and  direct  experiment,  there  is  no 
certain  evidence  that  the  sun  is  hotter  at  one  time  than  at 
another. 

If  we  investigate,  however,  the  connection  between  spots 
and  terrestrial  magnetic  disturbances,  we  shall  find  altogether 
more  satisfactory  testimony.  This  evidence  is  of  all  degrees  of 
strength,  from  probability  up  to  what  may  be  called  certainty, 
and  it  is  always  obtained,  not  by  a  priori  reasoning,  but  by  the 
comparison  of  independent  observations  of  something  which  has 
happened  on  the  sun  and  on  the  earth.  We  will  first  take  an 
instance  of  what  we  consider  the  weakest  degree  of  evidence 
(weak,  that  is,  when  any  such  single  case  is  considered),  and 
we  do  so  by  simply  quoting  textually  three  records  which  were 
made  at  nearly  the  same  time  in  different  parts  of  the  world 
in  1882. 


84  THE  NEW  ASTRONOMY. 

A  certain  spot  had  been  visible  on  the  sun  at  intervals  for 
some  weeks;  but  when  on  the  16th  of  November  a  glimpse  was 
caught  of  it  after  previous  days  of  cloudy  weather,  the  observer, 
it  will  be  seen,  is  struck  by  the  great  activity  going  on  in  it, 
and,  though  familiar  with  such  sights,  describes  this  one  as 
"  magnificent." 

1.  From  the  daily  record  at  the  Allegheny  Observatory,  No- 
vember 16,  1882:- 

"Very  large  spot  on  the  sun;  .  .  .  great  variety  of  forms;  inrush 
from  S.  E.  to  S.  W. ;  tendency  to  cyclonic  action  at  several  points.  The 
spot  is  apparently  near  its  period  of  greatest  activity.  A  magnificent 
sight." 

At  the  same  time  a  sketch  was  commenced  which  was  inter- 
rupted by  the  cloudy  weather  of  this  and  following  days.  The 
outline  of  the  main  spot  only  is  here  given  (Fig.  49).  Its  area, 
as  measured  at  Allegheny,  was  2,200,000,000  square  miles ;  at 
Greenwich  its  area,  inclusive  of  some  outlying  portions,  was 
estimated  on  the  same  day  to  be  2,600,000,000  square  miles. 
The  earth  is  shown  of  its  relative  size  upon  it,  to  give  a  proper 
idea  of  the  scale. 

2.  From  the  "New  York  Tribune"  of  November  18th  (de- 
scribing what  took  place  in  the  night  preceding  the  17th):  — 

AN   ELECTRIC   STORM/ 

TELEGRAPH   WIRES  GREATLY  AFFECTED. 

THE   DISTURBANCE   WIDE-SPREAD. 

...  At  the  Mutual  Union  office  the  manager  said,  "  Our  wires  are 
all  running,  but  very  slowly.  There  is  often  an  intermission  of  from  one 
to  five  minutes  between  the  words  of  a  sentence.  The  electric  storm  is 
general  as  far  as  our  wires  are  concerned."  .  .  .  The  cable  messages  were 
also  delayed,  in  some  cases  as  much  as  an  hour. 

The  telephone  service  was  practically  useless  during  the  day. 

WASHINGTON,  Nov.  17.  —  A  magnetic  storm  of  more  than  usual 
intensity  began  here  at  an  early  hour  this  morning,  and  has  continued 


THE  SUN'S  ENERGY.  85 

with  occasional  interruptions  during  the  day,  seriously  interfering  with 
telegraphic  communication.  ...  As  an  experiment  one  of  the  wires  of 
the  Western  Union  Telegraph  Company  was  worked  between  Washington 
and  Baltimore  this  afternoon  with  the  terrestrial  current  alone,  the 
batteries  having  been  entirely  detached. 

CHICAGO,  Nov.  17.  —  An  electric  storm  of  the  greatest  violence  raged 
in  all  the  territory  to  points  beyond  Omaha.  .  .  .  The  switch-board  here 
has  been  on  fire  a  dozen  times  during  the  forenoon.  At  noon  only  a  single 
wire  out  of  fifteen  between  this  city  and  New  York  was  in  operation. 

And  so  on  through  a  column. 

3.  In  Fig.  50  we  give  a  portion  of  the  automatic  trace  of  the 
magnetic  needles  at  Greenwich.1  These  needles  are  mounted 
on  massive  piers  in  the  cellars  of  the  observatory,  far  removed 
from  every  visible  source  of  disturbance,  and  each  carries  a 
small  mirror,  whence  a  spot  of  light  is  reflected  upon  a  strip  of 
photographic  paper,  kept  continually  rolling  before  it  by  clock- 
work. If  the  needle  is  still,  the  moving  strip  of  paper  will  have 
a  straight  line  on  it,  traced  by  the  point  of  light,  which  is  in  this 
case  motionless.  If  the  needle  swings  to  the  right  or  left,  the 
light-spot  vibrates  with  it,  and  the  line  it  traces  becomes  sinuous, 
or  more  and  more  sharply  zigzagged  as  the  needle  shivers  under 
the  unknown  forces  which  control  it. 

The  upper  part  of  Fig.  50  gives  a  little  portion  of  this  auto- 
matic trace  on  November  16th  before  the  disturbance  began,  to 
show  the  ordinary  daily  record,  which  should  be  compared  with 
the  violent  perturbation  occurring  simultaneously  with  the  tele- 
graphic disturbance  in  the  United  States.  We  may,  for  the 
reader's  convenience,  remark  that  as  the  astronomical  day  begins 
twelve  hours  later  than  the  civil  day,  the  approximate  Wash- 
ington mean  times,  corresponding  to  the  Greenwich  hours  after 

1  It  appears  here  through  the  kindness  of  the  Astronomer  Royal.  We  regret  to  say 
that  American  observers  are  dependent  on  the  courtesy  of  foreign  ones  in  such  matters, 
the  United  States  having  no  observatory  where  such  records  of  sun-spots  and  magnetic 
variation  are  systematically  kept. 


88  THE  NEW  ASTRONOMY. 

that  his  first  thought  was  that  daylight  was  entering  through 
a  hole  in  the  darkening  screen  he  used.  It  was  immediately, 
however,  made  certain  that  something  unusual  was  occurring 
in  the  sun  itself,  across  which  the  brilliant  spots  were  moving, 
travelling  thirty-five  thousand  miles  in  five  minutes,  at  the  end 
of  which  time  (at  twenty-three  minutes  past  eleven)  they  dis- 
appeared from  sight.  By  good  fortune,  another  observer  a  few 
miles  distant  saw  and  independently  described  the  same  phe- 
nomenon ;  and  as  the  minute  had  been  noted,  it  was  immedi- 
ately afterward  found  that  recording  instruments  registered  a 
magnetic  disturbance  at  the  same  time,  —  "at  the  very  moment," 
says  Dr.  Stewart,  the  director  of  the  observatory  at  Kew. 

"By  degrees,"  says  Sir  John  Herschel,  "accounts  began  to 
pour  in  of  ...  great  electro-magnetic  disturbances  in  every 
part  of  the  world.  ...  At  Washington  and  Philadelphia,  in 
America,  the  telegraphic  signal  men  received  severe  electric 
shocks.  At  Boston,  in  North  America,  a  flame  of  fire  followed 
the  pen  of  Bain's  electric  telegraph."  (Such  electric  disturb- 
ances, it  may  be  mentioned,  are  called  "  electric  storms,"  though 
when  they  occur  the  weather  may  be  perfectly  serene  to  the 
eye.  They  are  shown  also  by  rapid  vibrations  of  the  magnetic 
needle,  like  those  we  have  illustrated ) 

On  Aug.  3,  1872,  Professor  Young,  who  was  observing  at 
Sherman  in  the  Rocky  Mountains,  saw  three  notable  paroxysms 
in  the  sun's  chromosphere,  jets  of  luminous  matter  of  intense 
brilliance  being  projected  at  8h.  45m.,  lOh.  30m.,  and  llh.  50m. 
of  the  local  time.  "  At  dinner,"  he  says,  "the  photographer  of 
the  party,  who  was  making  our  magnetic  observations,  told  me, 
before  knowing  anything  about  what  I  had  been  observing,  that 
he  had  been  obliged  to  give  up  work,  his  magnet  having  swung 
clear  off  the  limb."  Similar  phenomena  were  observed  August 
5th.  Professor  Young  wrote  to  England,  and  received  from 
Greenwich  and  Stonyhtirst  copies  of  the  automatic  record, 


THE  SUN'S  ENERGY.  89 

which  he  gives,  and  which  we  give  in  Fig.  52.  After  allowing 
for  difference  of  longitude,  the  reader  who  will  take  the  pains 
to  compare  them  may  see  for  himself  that  both  show  a  jump  of 
the  needles  in  the  cellars  at  Greenwich  at  the  same  minute  in 
each  of  the  four  cases  of  outburst  in  the  Rocky  Mountains. 

While  we  admit  that  the  evidence  in  any  single  case  is  rarely 
so  conclusive  as  in  these ;  while  we  agree  that  the  spot  is  not  so 


FIG.    f>2.  —  GREENWICH   MAGNETIC   OBSERVATIONS,    AUG.    3   AND   5,    1872. 

much  the  cause  of  the  change  as  the  index  of  some  other  solar 
action  which  does  cause  it ;  and  while  we  fully  concede  our 
present  ignorance  of  the  nature  of  this  cause, — we  cannot  re- 
fuse to  accept  the  cumulative  evidence,  of  which  a  little  has 
been  submitted. 

It  is  only  in  rare  cases  that  we  can  feel  quite  sure ;  and  yet, 
in  regard  even  to  one  of  the  more  common  and  less  conclusive 
ones,  we  may  at  least  feel  warranted  in  saying  that  if  the  reader 
forfeited  a  business  engagement  or  missed  an  invitation  to  dinner 
through  the  failure  of  the  telegraph  or  telephone  on  such  an 


86  THE  NEW  ASTRONOMY. 

twelve,  are  found  by  adding  one  to  the  days  and  subtracting 
seventeen  from  the  hours.  Thus  "  November  16th,  twenty-two 
hours "  corresponds  in  the  eastern  United  States  nearly  to  five 
o'clock  in  the  morning  of  November  17th. 

The  Allegheny  observer,  it  will  be  remembered,  in  his 
glimpse  of  the  spot  on  November  16th,  was  struck  with  the 
great  activity  of  the  internal  motions  then  going  on  in  it.  The 
Astronomer  Royal  states  that  a  portion  of  the  spot  became 
detached  on  November  17th  or  18th,  and  that  several  small 
spots  which  broke  out  in  the  immediate  neighborhood  were 
seen  for  the  first  time  on  the  photographs  taken  November 
17th,  twenty-two  hours. 

"  Are  we  to  conclude  from  this,"  it  may  be  asked,  "  that  what 
went  on  in  the  sun  was  the  cause  of  the  trouble  on  the  telegraph 
wires  ?  "  I  think  we  are  not  at  all  entitled  to  conclude  so  from 
this  instance  alone ;  but  though  in  one  such  case,  taken  by  itself, 
there  is  nothing  conclusive,  yet  when  such  a  degree  of  coinci- 
dence occurs  again  and  again,  the  habitual  observer  of  solar 
phenomena  learns  to  look  with  some  confidence  for  evidence  of 
electrical  disturbance  here  following  certain  kinds  of  disturbance 
there,  and  the  weight  of  this  part  of  the  evidence  is  not  to  be 
sought  so  much  in  the  strength  of  a  single  case,  as  in  the 
multitude  of  such  coincidences. 

We  have,  however,  not  only  the  means  of  comparing  sun- 
spot  years  with  years  of  terrestrial  electric  disturbance,  but 
individual  instances,  particular  minutes  of  sun-spot  changes,  with 
particular  minutes  of  terrestrial  change ;  and  both  comparisons 
are  of  the  most  convincing  character. 

First,  let  us  observe  that  the  compass  needle,  in  its  regular 
and  ordinary  behavior,  does  not  point  constantly  in  any  one  di- 
rection through  the  day,  but  moves  a  very  little  one  way  in 
the  morning,  and  back  in  the  afternoon.  This  same  movement, 
which  can  be  noticed  even  in  a  good  surveyor's  compass,  is 


THE  SUN'S  ENERGY. 


87 


called  the  "  diurnal  oscillation,"  and  has  long  been  known.  It 
has  been  known,  too,  that  its  amount  altered  from  one  year  to 
another ;  but  since  Schwabe's  observations  it  has  been  found  that 
the  changes  in  this  variation  and  in  the  number  of  the  spots  went 
on  together.  The  coincidences  which  we  failed  to  note  in  the 
comparison  of  the  spots  with  the  prices  of  grain  are  here  made 
out  with  convincing  clearness,  as  the  reader  will  see  by  a  simple 
inspection  of  this  chart  (Fig.  51,  taken  from  Professor  Young's 


J 


7T 


- 


1810 


1820  IS30  1940 

FIG.    51.  —  SUN-SPOTS   AND   MAGNETIC   VARIATIONS. 


1850 


work),  where  the  horizontal  divisions  still  denote  years,  and  the 
height  of  the  continuous  curve  the  relative  number  of  spots, 
while  the  height  of  the  dotted  curve  is  the  amount  of  the  mag- 
netic variation.  Though  we  have  given  but  a  part  of  the  curve, 
.  the  presumption  from  the  agreement  in  the  forty  years  alone 
would  be  a  strong  one  that  the  two  effects,  apparently  so  widely 
remote  in  their  nature,  are  really  due  to  a  common  cause. 

Here  we  have  compared  years  with  years ;  let  us  next  com- 
pare minutes  with  minutes.  Thus,  to  cite  (from  Mr.  Proctor's 
work)  a  well-known  instance:  On  Sept.  1,  1869,  at  eighteen  min- 
utes past  eleven,  Mr.  Carrington,  an  experienced  solar  observer, 
suddenly  saw  in  the  sun  something  brighter  than  the  sun,  — 
two  patches  of  light,  breaking  out  so  instantly  and  so  intensely 


90  THE  NEW  ASTRONOMY. 

occasion  as  that  of  the  17th  of  November,  1882,  the  far-off  sun- 
spot  was  not  improbably  connected  with  the  cause. 

Probably  we  should  all  like  to  hear  some  at  least  equally 
positive  conclusion  about  the  weather  also,  and  to  learn  that 
there  was  a  likelihood  of  our  being  able  to  predict  it  for  the  next 
year,  as  the  Signal  Service  now  does  for  the  next  day ;  but  there 
is  at  present  no  such  likelihood.  The  study  of  the  possible  con- 
nection between  sun-spots  and  the  weather  is,  nevertheless,  one 
that  will  always  have  great  interest  to  many ;  for  even  if  we  set 
its  scientific  aim  aside  and  consider  it  in  its  purely  utilitarian 
aspect,  it  is  evident  that  the  knowledge  how  to  predict  whether 
coming  harvests  would  be  good  or  bad,  would  enable  us  to  do 
for  the  whole  world  what  Joseph's  prophetic  vision  of  the  seven 
good  and  seven  barren  years  did  for  the  land  of  Egypt,  and 
confer  a  greater  power  on  its,  discoverer  than  any  sovereign  now 
possesses.  There  is  something  to  be  said,  then,  for  the  cyclists ; 
for  if  their  zeal  does  sometimes  outrun  knowledge,  their  object 
is  a  worthy  one,  and  their  aims  such  as  we  can  sympathize  with, 
and  of  which  none  of  us  can  say  that  there  is  any  inherent  im- 
possibility in  them,  or  that  they  may  not  conceivably  yet  lead 
to  something.  Let  us  not,  then,  treat  the  inquirer  who  tries  to 
connect  panics  on  'Change  with  sun-spots  as  a  mere  lunatic ;  for 
there  is  this  amount  of  reason  in  his  theory,  that  the  panics, 
together  with  the  general  state  of  business,  are  connected  in 
some  obscure  way  with  the  good  or  bad  harvests,  and  these 
again  in  some  still  obscurer  way  with  changes  in  our  sun. 

We  may  leave,  then,  this  vision  of  forecasting  the  harvests 
and  the  markets  of  the  world  from  a  study  of  the  sun,  as  one  of 
the  fair  dreams  for  the  future  of  our  science.  Perhaps  the  dream 
will  one  day  be  realized.  Who  knows  ? 


IV. 

THE   SUN'S   ENERGY  (Continued). 

IF  we  paused  on  the  words  with  which  our  last  chapter  closed, 
the  reader  might  perhaps  so  far  gather  an  impression  that 
the  whole  all-important  subject  of  the  solar  energy  was  involved 
in  mystery  and  doubt.  But  if  it  be  indeed  a  mystery  when 
considered  in  its  essence,  so  are  all  things ;  while  regarded  sepa- 
rately in  any  one  of  its  terrestrial  effects  of  magnetic  or  chemical 
action,  or  of  light  or  heat,  it  may  seem  less  so.  Since  there  is 
not  room  to  consider  all  these  aspects,  let  us  choose  the  last, 
and  look  at  this  energy  in  its  familiar  form  of  the  heat  by  which 
we  live. 

We,  the  human  race,  are  warming  ourselves  at  this  great  fire 
which  called  our  bodies  into  being,  and  when  it  goes  out  we 
shall  go  too.  What  is  it  ?  How  long  has  it  been  ?  How  long 
will  it  last?  How  shall  we  use  it? 

To  look  across  the  space  of  over  ninety  million  miles,  and  to 
try  to  learn  from  that  distance  the  nature  of  the  solar  heat,  and 
how  it  is  kept  up,  seemed  to  the  astronomers  of  the  last  century 
a  hopeless  task.  The  difficulty  was  avoided  rather  than  met  by 
the  doctrine  that  the  sun  was  pure  fire,  and  shone  because  "it 
was  its  nature  to."  In  the  Middle  Ages  such  an  idea  was  uni- 
versal; and  along  with  it,  and  as  a  logical  sequence  of  it,  the 
belief  was  long  prevalent  that  it  was  possible  to  make  another 
such  flame  here,  in  the  form  of  a  lamp  which  should  burn  for- 
ever and  radiate  light  endlessly  without  exhaustion.  With  the 


92  THE  NEW  ASTRONOMY. 

philosopher's  stone,  which  was  to  transmute  lead  into  gold,  this 
perpetual  lamp  formed  a  prime  object  of  research  for  the  al- 
chemist and  student  of  magic. 

We  recall  the  use  which  Scott  has  made  of  the  belief  in  this 
product  of  "gramarye"  in  the  "  Lay  of  the  Last  Minstrel," 
where  it  is  sought  to  open  the  grave  of  the  great  wizard  in 
Melrose  Abbey.  It  is  midnight  when  the  stone  which  covers 
it  is  heaved  away,  and  Michael's  undying  lamp,  buried  with  him 
long  ago,  shines  out  from  the  open  tomb  and  illuminates  the 
darkness  of  the  chancel. 

"I  would  you  had  been  there  to  see 
The  light  break  forth  so  gloriously; 
That  lamp  shall  burn  unquenchably 
Until  the  eternal  doom  shall  be," 

says  the  poet.  Now  we  are  at  liberty  to  enjoy  the  fiction  as  a 
fiction ;  but  if  we  admit  that  the  art  which  could  make  such  a 
lamp  would  indeed  be  a  black  art,  which  did  not  work  under 
Nature's  laws,  but  against  them,  then  we  ought  to  see  that  as  the 
whole  conception  is  derived  from  the  early  notion  of  a  miracu- 
lous constitution  of  the  sun,  the  idea  of  an  eternal  self-sustained 
sun  is  no  more  permitted  to  us  than  that  of  an  eternal  self- 
sustained  lamp.  We  must  look  for  the  cause  of  the  sun's  heat 
in  Nature's  laws,  and  we  know  those  laws  chiefly  by  what  we 
see  here. 

Before  examining  the  source  of  the  sun's  heat,  let  us  look  a 
little  more  into  its  amount.  To  find  the  exact  amount  of  heat 
which  it  sends  out  is  a  very  difficult  problem,  especially  if  we 
are  to  use  all  the  refinements  of  the  latest  methods  in  deter- 
mining it.  The  underlying  principle,  however,  is  embodied  in 
an  old  method,  which  gives,  it  is  true,  rather  crude  results,  but 
by  so  simple  a  treatment  that  the  reader  can  follow  it  readily, 
especially  if  unembarrassed  with  details,  in  which  most  of  the 
actual  trouble  lies.  We  must  warn  him  in  advance  that  he  is 


THE  SUN'S  ENERGY. 


93 


FIG.  53.  —  ONE  CUBIC 
CENTIMETRE. 


going  to  be  confronted  with  a  kind  of  enormous  sum  in  multi- 
plication, for  whose  general  accuracy  he  may,  however,  trust  to 
us  if  he  pleases.  We  have  not  attempted  exact  accuracy,  be- 
cause it  is  more  convenient  for  him  that  we  should  deal  with 
round  numbers. 

The  apparatus  which  we  shall  need  for  the  attack  of  this 
great  problem  is  surprisingly  simple,  and  moderate  in  size.  Let 
us  begin  by  finding  how  much  sun-heat  falls  in  a  small  known 
area.  To  do  this  we  take  a  flat,  shallow  vessel, 
which  is  to  be  filled  with  water.  The  amount  it 
contains  is  usually  a  hundred  cubic  centimetres  (a 
centimetre  being  nearly  four-tenths  of  an  inch),  so 
that  if  we  imagine  a  tiny  cubical  box  about  as 
large  as  a  backgammon  die,  or,  more  exactly, 
having  each  side  just  the  size  of  this  (Fig.  53),  to 
be  filled  and  emptied  into  the  vessel  one  hundred  times,  we 
shall  have  a  precise  idea  of  its  limited  capacity. 
Into  this  vessel  we  dip  a  thermometer,  so  as  to 
read  the  temperature  of  the  water,  seal  all  up  so 
that  the  water  shall  not  run  out,  and  expose  it  so 
that  the  heat  at  noon  falls  perpendicularly  on  it. 
The  apparatus  is  shown  in  Fig.  54,  attached  to 
a  tree.  The  stem  of  the  instrument  holds  the 
thermometer,  which  is  upside  down,  its  bulb  being 
in  the  water-vessel.  Now,  all  the  sun's  rays  do 
not  reach  this  vessel,  for  some  are  absorbed  by 
our  atmosphere  ;  and  all  the  heat  which  falls  on 
it  does  not  stay  there,  as  the  water  loses  part  of 
it  by  the  contact  of  the  air  with  the  box  outside, 
and  in  other  ways.  When  allowance  is  made  for  these  losses, 
we  find  that  the  sun's  heat,  if  all  retained,  would  have  raised  the 
temperature  of  the  few  drops  of  water  which  would  fill  a  box 
the  size  of  our  little  cube  (according  to  these  latest  observa- 


FIG.  54.  - 

PYRHELIOMETER. 


94  THE  NEW  ASTRONOMY. 

tions)  nearly  three  degrees  of  the  centigrade  thermometer  in 
one  minute,  —  a  most  insignificant  result,  apparently,  as  a  meas- 
ure of  what  we  have  been  told  is  the  almost  infinite  heat  of 
the  sun !  But  if  we  think  so,  we  are  forgetting  the  power 
of  numbers,  of  which  we  are  about  to  have  an  illustration  as 
striking  in  its  way  as  that  which  Archimedes  once  gave  with 
the  grains  of  sand. 

There  is  a  treatise  of  his  extant,  in  which  he  remarks  (I  cite 
from  memory)  that  as  some  people  believe  it  possible  for  numbers 
to  express  a  quantity  as  great  as  that  of  the  grains  of  sand  upon 
the  sea-shore,  while  others  deny  this,  he  will  show  that  they 
can  express  one  even  larger.  To  prove  this  beyond  dispute,  he 
begins  by  taking  a  small  seed,  beside  which  he  ranges  single 
grains  of  sand  in  a  line,  till  he  can  give  the  number  of  these  lat- 
ter which  equal  its  length.  Next  he  ranges  seeds  beside  each 
other  till  their  number  makes  up  the  length  of  a  span ;  then  he 
counts  the  spans  in  a  stadium,  and  the  stadia  in  the  whole  world 
as  known  to  the  ancients,  at  each  step  expressing  his  results  in 
a  number  certainly  greater  than  the  number  of  sand-grains  which 
the  seed,  or  the  span,  or  the  stadium,  or  finally  the  whole  world, 
is  thus  successively  shown  to  contain.  He  has  then  already  got 
a  number  before  his  reader's  eyes  demonstrably  larger  than  that 
of  all  the  grains  of  sand  on  the  sea-shore  ;  yet  he  does  not  stop, 
but  steps  off  the  earth  into  space,  to  calculate  and  express  a 
number  greater  than  that  of  all  the  grains  of  sand  which  would 
fill  a  sphere  embracing  the  earth  and  the  sun ! 

We  are  going  to  use  our  little  unit  of  heat  in  the  same  way, 
for  (to  calculate  in  round  figures  and  in  English  measure)  we 
find  that  we  can  set  over  nine  hundred  of  these  small  cubes  side- 
by  side  in  a  square  foot,  and,  as  there  are  28,000,000  feet  in  a 
square  mile,  that  the  latter  would  contain  25,000,000,000  of  the 
cubes,  placed  side  by  side,  touching  each  other,  like  a  mosaic 
pavement.  We  find  also,  by  weighing  our  little  cup,  that  we 


T1IK  SUN^S  ENERGY.  95 

should  need  to  fill  and  empty  it  almost  exactly  a  million  times  to 
exhaust  a  tank  containing  a  ton  of  water.  The  sun-heat  falling 
on  one  square  mile  corresponds,  then,  to  over  seven  hundred 
and  fifty  tons  of  water  raised  every  minute  from  the  freezing- 
point  to  boiling,  which  already  is  becoming  a  respectable 
amount ! 

But  there  are  49,000,000  square  miles  in  the  cross-section  of 
the  earth  exposed  to  the  sun's  rays,  which  it  would  therefore 
need  1,225,000,000,000,000,000  of  our  little  dies  to  cover  one 
deep ;  and  therefore  in  each  minute  the  sun's  heat  falling  on 
the  earth  would  raise  to  boiling  37,000,000,000  tons  of  water. 

We  may  express  this  in  other  ways,  as  by  the  quantity  of 
ice  it  would  melt;  and  as  the  heat  required  to  melt  a  given 
weight  of  ice  is  T7o\  of  that  required  to  bring  as  much  water 
from  the  freezing  to  the  boiling  point,  arid  as  the  whole  surface 
of  the  earth,  including  the  night  side,  is  four  times  the  cross- 
section  exposed  to  the  sun,  we  find,  by  taking  526,000  minutes 
to  a  year,  that  the  sun's  rays  would  melt  in  the  year  a  coating 
of  ice  over  the  whole  earth  more  than  one  hundred  and  sixty 
feet  thick. 

We  have  ascended  already  from  our  small  starting-point  to 
numbers  which  express  the  heat  that  falls  upon  the  whole  planet, 
and  enable  us  to  deal,  if  we  wish,  with  questions  relating  to 
the  glacial  epochs  and  other  changes  in  its  history.  We  have 
done  this  by  referring  at  each  step  to  the  little  cube  which  we 
have  carried  along  with  us,  and  which  is  the  foundation  of  all 
the  rest ;  and  we  now  see  why  such  exactness  in  the  first  deter- 
mination is  needed,  since  any  error  is  multiplied  by  enormous 
numbers.  But  now  we  too  are  going  to  step  off  the  earth  and 
to  deal  with  numbers  which  we  can  still  express  in  the  same  way 
if  we  choose,  but  which  grow  so  large  thus  stated  that  we  will 
seek  some  greater  term  of  comparison  for  them.  We  have  just 
seen  the  almost  incomprehensible  amount  of  heat  which  the  sun 


96  THE  NEW  ASTRONOMY. 

must  send  the  earth  in  order  to  warm  its  oceans  and  make  green 
its  continents ;  but  how  little  this  is  to  what  passes  us  by  !  The 
earth  as  it  moves  on  in  its  annual  path  continually  comes  into 
new  regions,  where  it  finds  the  same  amount  of  heat  already 
pouring  forth  ;  and  this  same  amount  still  continues  to  fall  into 
the  empty  space  we  have  just  quitted,  where  there  is  no  one 
left  to  note  it,  and  where  it  goes  on  in  what  seems  to  us  utter 
waste.  If,  then,  the  whole  annual  orbit  were  set  close  with 
globes  like  ours,  and  strung  with  worlds  like  beads  upon  a 
ring,  each  would  receive  the  same  enormous  amount  the  earth 
does  now.  But  this  is  not  all  ;  for  not  only  along  the  orbit, 
but  above  and  below  it,  the  sun  sends  its  heat  in  seemingly 
incredible  wastefulness,  the  final  amount  being  expressible  in 
the  number  of  icorM*  like  ours  that  it  could  warm  like  ours, 
which  is  2,200,000,000. 

We  have  possibly  given  a  surfeit  of  such  numbers,  but  we 
cannot  escape  or  altogether  avoid  them  when  dealing  witli  this 
stupendous  outflow  of  the  solar  heat.  They  are  too  great,  per- 
haps, to  convey  a  clear  idea  to  the  mind,  but  let  us  before  leav- 
ing them  try  to  give  an  illustration  of  'their  significance. 

Let  us  suppose  that  we  could  sweep  up  from  the  earth  all  the 
ice  and  snow  on  its  surface,  and,  gathering  in  the  accumulations 
which  lie  on  its  Arctic  and  Antarctic  poles,  commence  building 
with  it  a  tower  greater  than  that  of  Babel,  fifteen  miles  in  diam- 
eter, and  so  high  as  to  exhaust  our  store.  Imagine  that  it  could 
be  preserved  untouched  by  the  sun's  rays,  while  we  built  on 
with  the  accumulations  of  successive  winters,  until  it  stretched 
out  240,000  miles  into  space,  and  formed  an  ice-bridge  to  the 
moon,  and  that  then  we  concentrated  on  it  the  sun's  whole  radia- 
tion, neither  more  nor  less  than  that  which  goes  on  every  mo- 
ment. In  one  second  the  whole  would  be  gone,  melted,  boiled, 
and  dissipated  in  vapor.  And  this  is  the  rate  at  which  the  solar 
heat  is  being  (to  human  apprehension)  wasted! 


THE  SUN'S  ENERGY.  97 

Nature,  we  are  told,  always  accomplishes  her  purpose  with 
the  least  possible  expenditure  of  energy.  Is  her  purpose  here, 
then,  something  quite  independent  of  man's  comfort  and  hap- 
piness! Of  the  whole  solar  heat,  we  have  just  seen  that  less 
than  2>0w)000,  —  less,  that  is,  than  the  one  twenty-thousandth  part 
of  one  per  cent,  —  is  made  useful  to  us.  "But  may  there  not 
be  other  planets  on  which  intelligent  life  exists,  and  where  this 
heat,  which  passes  us  by,  serves  other  beings  than  ourselves  ?  " 
There  may  be;  but  if  we  could  suppose  all  the  other  planets 
of  the  solar  system  to  be  inhabited,  it  would  help  the  matter 
very  little ;  for  the  whole  together  intercept  so  little  of  the  great 
sum,  that  all  of  it  which  Nature  bestows  on  man  is  still  as  noth- 
ing to  what  she  bestows  on  some  end  —  if  end  there  be  —  which 
is  to  us  as  yet  inscrutable. 

How  is  this  heat  maintained  ?  Not  by  the  miracle  of  a  per- 
petual self-sustained  flame,  we  may  be  sure.  But,  then,  by  what 
fuel  is  such  a  fire  fed?  There  can  be  no  question  of  simple 
burning,  like  that  of  coal  in  the  grate,  for  there  is  no  source  of 
supply  adequate  to  the  demand.  The  State  of  Pennsylvania, 
for  instance,  is  underlaid  by  one  of  the  richest  coal-fields  of  the 
world,  capable  of  supplying  the  consumption  of  the  whole  coun- 
try at  its  present  rate  for  more  than  a  thousand  years  to  come. 
If  the  source  of  the  solar  heat  (whatever  that  is)  were  withdrawn, 
and  we  were  enabled  to  carry  this  coal  there,  and  shoot  it  into 
the  solar  furnace  fast  enough  to  keep  up  the  known  heat-supply, 
so  that  the  solar  radiation  would  go  on  at  just  its  actual  rate,  the 
time  which  this  coal  would  last  is  easily  calculable.  It  would 
not  last  days  or  hours,  but  the  whole  of  these  coal-beds  would 
demonstrably  be  used  up  in  rather  less  than  one  one-thousandth 
of  a  second !  We  find  by  a  similar  calculation  that  if  the  sun 
were  itself  one  solid  block  of  coal,  it  would  have  burned  out  to 
the  last  cinder  in  less  time  than  man  has  certainly  been  on  the 
earth.  But  during  historic  times  there  has  as  surely  been  no 

7 


US  THE  A'A'ir  ASTRONOMY. 

noticeable  diminution  of  the  sun's  heat,  for  the  olive  and  the 
vine  grow  just  as  they  did  three  thousand  years  ago,  and  the 
hypothesis  of  an  actual  burning  becomes  untenable.  It  has 
been  supposed  by  some  that  meteors  striking  the  solar  surface 
might  generate  heat  by  their  impact,  just  as  a  cannon-ball  fired 
against  an  armor-plate  causes  a  flash  of  light,  and  a  heat  so 
sudden  and  intense  as  to  partly  melt  the  ball  at  the  instant  of 
concussion.,  This  is  probably  a  real  source  of  heat-supply  so  far 
as  it  goes,  but  it  cannot  go  very  far;  and,  indeed,  if  our  whole 
world  should  fall  upon  the  solar  surface  like  an  immense  pro- 
jectile, gathering  speed  as  it  fell,  and  finally  striking  (as  it 
would)  with  the  force  due  to  a  rate  of  over  three  hundred  miles 
a  second,  the  heat  developed  would  supply  the  sun  for  but  little 
more  than  sixty  years.1 

It  is  not  necessary,  however,  that  a  body  should  be  moving 
rapidly  to  develop  heat,  for  arrested  motion  always  generates  it, 
whether  the  motion  be  fast  or  slow,  though  in  the  latter  case  the 
mass  arrested  must  be  larger  to  produce  the  same  result.  It  is 
in  the  slow  settlement  of  the  sun's  own  substance  toward  its 
centre,  as  it  contracts  in  cooling,  that  we  find  a  sufficient  cause 
for  the  heat  developed. 

This  explanation  is  often  unsatisfactory  to  those  who  have 
not  studied  the  subject,  because  the  fact  that  heat  is  so  generated 
is  not  made  familiar  to  most  of  us  by  observation. 

Perhaps  the  following  illustration  will  make  the  matter 
plainer.  When  we  are  carried  up  in  a  lift,  or  elevator,  we 
know  well  enough  that  heat  has  been  expended  under  the 
boiler  of  some  engine  to  drag  us  up  against  the  power  of 
gravity.  When  the  elevator  is  at  the  top  of  its  course,  it  is 
ready  to  give  out  in  descending  just  the  same  amount  of  power 
needed  to  raise  it,  as  we  see  by  its  drawing  up  a  nearly  equal 

1  These  estimates  differ  ><>inc\vli;it   from   those  of  Helmholtz  and  Tyndall,  as  they 

rest  on  later  measures. 


THE  SUN'S  ENERGY.  00 

counterpoise  in  the  descent.  It  can  and  must  give  out  in  com- 
ing- down  the  power  that  was  spent  in  raising  it  up  ;  and  though 
there  is  no  practical  occasion  to  do  so,  a  large  part  of  this  power 
could,  if  we  wished,  be  actually  recovered  in  the  form  of  heat 
ngain.  In  the  case  of  a  larger  body,  such  as  the  pyramid  of 
Ghizeh,  which  weighs  between  six  and  seven  million  tons, 
all  the  furnaces  in  the  world,  burning  coal  under  all  its  engines, 
would  have  to  supply  their  heat  for  a  measurable  time  to  lift  it  a 
mile  high ;  and  then,  if  it  were  allowed  to  come  down,  whether 
it  fell  at  once  or  were  made  to  descend  with  imperceptible  slow- 
ness, by  the  time  it  touched  the  earth  the  same  heat  would  be 
given  out  again. 

Perhaps  the  fact  that  the  sun  is  gaseous  rather  than  solid 
makes  it  less  easy  to  realize  the  enormous  weight  which  is  con- 
sistent with  this  vaporous  constitution.  A  cubic  mile  of  hydro- 
gen gas  (the  lightest  substance  knowrn)  would  weigh  much  more 
at  the  sun's  surface  than  the  Great  Pyramid  does  here,  and  the 
number  of  these  cubic  miles  in  a  stratum  one  mile  deep  below 
its  surface  is  over  2,000,000,000,000!  This  alone  is  enough 
to  show  that  as  they  settle  downward  as  the  solar  globe 
shrinks,  here  is  a  possible  source  of  supply  for  all  the  heat  the 
sun  sends  out.  More  exact  calculation  shows  that  it  is  sufficient, 
and  that  a  contraction  of  three  hundred  feet  a  year  (which  in  ten 
thousand  years  would  make  a  shrinkage  hardly  visible  in  the 
most  powerful  telescope)  would  give  all  the  immense  outflow  of 
heat  which  we  see. 

There  is  an  ultimate  limit,  however,  to  the  sun's  shrinking, 
and  there  must  have  been  some  bounds  to  the  heat  he  can 
already  have  thus  acquired;  for  —  though  the  greater  the 
original  diameter  of  his  sphere,  the  greater  the  gain  of  heat 
by  shrinking  to  its  present  size  —  if  the  original  diameter  be 
supposed  as  great  as  possible,  there  is  still  a  finite  limit  to  the 
heat  gained. 


100  THE  NEW  ASTRONOMY. 

Suppose,  in  other  words,  the  sun  itself  and  all  the  planets 
ground  to  powder,  and  distributed  on  the  surface  of  a  sphere 
whose  radius  is  infinite,  and  that  this  matter  (the  same  in 
amount  as  that  constituting-  the  present  solar  system)  is  allowed 
to  fall  together  at  the  centre.  The  actual  shrinkage  cannot 
possibly  be  greater  than  in  this  extreme  case ;  but  even  in  this 
practically  impossible  instance,  it  is  easy  to  calculate  that  the 
heat  given  out  would  not  support  the  present  radiation  over 
eighteen  million  years,  and  thus  we  are  enabled  to  look  back 
over  past  time,  and  fix  an  approximate  limit  to  the  age  of  the 
sun  and  earth. 

We  say  "present"  rate  of  radiation,  because,  so  long  as  the 
sun  is  purely  gaseous,  its  temperature  rises  as  it  contracts,  and 
the  heat  is  spent  faster ;  so  that  in  early  ages  before  this  tem- 
perature was  as  high  as  it  is  now,  the  heat  was  spent  more 
slowly,  and  w^hat  could  have  lasted  "only"  eighteen  million 
years  at  the  present  rate  might  have  actually  spread  over  an 
indefinitely  greater  time  in  the  past;  possibly  covering  more 
than  all  the  aeons  geologists  ask  for. 

If  we  would  look  into  the  future,  also,  we  find  that  at  the 
present  rate  we  may  say  that  the  sun's  heat-supply  is  enough  to 
last  for  some  such  term  as  four  or  five  million  years  before  it 
sensibly  fails.  It  is  certainly  remarkable  that  by  the  aid  of  our 
science  man  can  look  out  from  this  "bank  and  shoal  of  time," 
where  his  fleeting  existence  is  spent,  not  only  back  on  the  almost 
infinite  lapse  of  ages  past,  but  that  he  can  forecast  with  some 
sort  of  assurance  what  is  to  happen  in  an  almost  infinitely  distant 
future,  long  after  the  human  race  itself  will  have  disappeared 
from  its  present  home.  But  so  it  is,  and  we  may  say  —  with 
something  like  awe  at  the  meaning  to  which  science  points- 
that  the  whole  future  radiation  cannot  last  so  long  as  ten  million 
years.  Its  probable  life  in  its  present  condition  is  covered  by 
about  thirty  million  years.  No  reasonable  allowance  for  the  fall 


THE  SUN'S  ENERGY.  101 

of  meteors  or  for  all  other  known  causes  of  supply  could  pos- 
sibly at  the  present  rate  of  radiation  raise  the  whole  term  of  its 
existence  to  sixty  million  years. 

Tliis  is  substantially  Professor  Young's  view,  and  he  adds :  — 

"  At  the  same  time  it  is,  of  course,  impossible  to  assert  that  there  has 
been  no  catastrophe  in  the  past,  no  collision  with  some  wandering  star 
.  .  .  producing  a  shock  which  might  in  a  few  hours,  or  moments  even, 
restore  the  wasted  energy  of  ages.  Neither  is  it  wholly  safe  to  assume 
that  there  may  not  be  ways,  of  which  we  as  yet  have  no  conception,  by 
which  the  energy  apparently  lost  in  space  may  be  returned.  But  the 
whole  course  and  tendency  of  Nature,  so  far  as  science  now  makes 
out,  points  backward  to  a  beginning  and  forward  to  an  end.  The 
present  order  of  things  seems  to  be  bounded  both  in  the  past  and  in 
the  future  by  terminal  catastrophes  which  are  veiled  in  clouds  as  yet 
inscrutable." 

There  is  another  matter  of  interest  to  us  as  dwellers  on  this 
planet,  connected  not  with  the  amount  of  the  sun's  heat  so  much 
as  with  the  degree  of  its  temperature ;  for  it  is  almost  certain 
that  a  very  little  fall  in  the  temperature  will  cause  an  immense 
and  wholly  disproportionate  diminution  of  the  heat-supply.  The 
same  principle  may  be  observed  in  more  familiar  things.  We 
can,  for  instance,  warm  quite  a  large  house  by  a  very  small  fur- 
nace, if  we  urge  this  (by  a  wasteful  use  of  coal)  to  a  dazzling 
white  heat.  If  we  now  let  the  furnace  cool  to  half  this  white- 
heat  temperature,  we  shall  be  sure  to  find  that  the  heat  radiated 
has  not  diminished  in  proportion,  but  out  of  all  proportion,  — 
has  sunk,  for  instance,  not  only  to  one-half  what  it  was  (as  we 
might  think  it  would  do),  but  to  perhaps  a  twentieth  or  even 
less,  so  that  the  furnace  which  heated  the  house  can  110  longer 
warm  a  single  room. 

o 

The  human  race,  as  we  have  said,  is  warming  itself  at  the 
great  solar  furnace,  which  we  have  just  seen  contains  an  internal 
source  for  generating  heat  enough  for  millions  of  years  to  come ; 
but  we  have  also  learned  that  if  the  sun's  internal  circulation 


102  THE  NEW  ASTRONOMY. 

were  stopped,  the  surface  would  cool  and  shut  up  the  heat 
inside,  where  it  would  do  us  no  good.  The  temperature  of  the 
surface,  then,  on  which  the  rate  of  heat-emission  depends,  con- 
cerns us  very  much ;  and  if  we  had  a  thermometer  so  long  that 
we  could  dip  its  bulb  into  the  sun  and  read  the  degrees  on  the 
stem  here,  we  should  find  out  what  observers  would  very  much 
like  to  know,  and  at  present  are  disposed  to  quarrel  about.  The 
difficulty  is  not  in  measuring  the  heat,  —  for  that  we  have  just 
seen  how  to  do,  —  but  in  telling  what  temperature  corresponds 
to  it,  since  there  is  no  known  rule  by  which  to  find  one  from  the 
other.  One  certain  thing  is  this  —  that  we  cannot  by  any  con- 
trivance raise  the  temperature  in  the  focus  of  any  lens  or  mirror 
beyond  that  of  its  source  (practically  we  cannot  do  even  so 
much) ;  we  cannot,  for  instance,  by  any  burning-lens  make  the 
image  of  a  candle  as  hot  as  the  original  flame.  Whatever  a 
thermometer  may  read  when  the  candle-heat  is  concentrated  on 
its  bulb  by  a  lens,  it  would  read  yet  more  if  the  bulb  were 
dipped  in  the  candle-flame  itself;  and  one  obvious  application 
of  this  fact  is  that  though  we  cannot  dip  our  thermometer  in  the 
sun,  we  know  that  if  we  could  do  so,  the  temperature  would  at 
least  be  greater  than  any  we  get  by  the  largest  burning-glass. 
We  need  have  no  fear  of  making  the  burning-glass  too  big ;  the 
temperature  at  its  solar  focus  is  always  and  necessarily  lower 
than  that  of  the  sun  itself. 

For  some  reason  no  very  great  burning-lens  or  mirror  has 
been  constructed  for  a  long  time,  and  we  have  to  go  back  to  the 
eighteenth  century  to  see  what  can  be  done  in  this  way.  The 
annexed  figure  (Fig.  55)  is  from  a  wood-cut  of  the  last  century, 
describing  the  largest  burning-lens  then  or  since  constructed 
in  France,  whose  size  and  mode  of  use  the  drawing  clearly 
shows.  All  the  heat  falling  on  the  great  lens  was  concen- 
trated on  a  smaller  one,  and  the  smaller  one  concentrated  it 
in  turn,  till  at  the  very  focus  we  are  assured  that  iron,  gold, 


SUN'S  ENERGY. 


103 


and  other  metals  ran  like  melted  butter.  In  England,  the 
largest  burning-lens  on  record  was  made  about  the  same  time 
by  an  optician  named  Parker  for  the  English  Government,  who 
designed  it  as  a  present  to  be  taken  by  Lord  Macartney's  em- 
bassy to  the  Emperor  of  China.  Parker's  lens  was  three  feet 
in  diameter  and  very  massive,  being  seven  inches  thick  at  the 


FIG.  55. — BERNIERES'S  GREAT  BURNING-GLASS.   (AFTER  AN  OLD  FRENCH  PRINT.) 

centre.  In  its  focus  the  most  refractory  substances  were  fused, 
and  even  the  diamond  was  reduced  to  vapor,  so  that  the 
temperature  of  the  sun's  surface  is  at  any  rate  higher  than 
this. 

(What  became  of  the  French  lens  shown,  it  would  be  inter- 
esting to  know.  If  it  is  still  above  ground,  its  fate  has  been 
better  than  that  of  the  English  one.  It  is  said  that  the  Emperor 
of  China,  when  he  got  his  lens,  was  much  alarmed  by  it,  as 
being  possibly  sent  him  by  the  English  with  some  covert 
design  for  his  injury.  .  By  way  of  a  test,  a  smith  was  ordered 


104  THE  NEW  ASTRONOMY. 

to  strike  it  with  his  hammer :  but  the  hammer  rebounded  from 
the  solid  glass,  and  this  was  taken  to  be  conclusive  evidence 
of  magic  in  the  thing,  which  was  immediately  buried,  and  prob- 
ably is  still  reposing  under  the  soil  of  the  Celestial  Flowery 
Kingdom.) 

We  can  confirm  the  evidence  of  such  burning-lenses  as  to 
the  sun's  high  temperature  by  another  class  of  experiment, 
which  rests  on  an  analogous  principle.  We  can  make  the 
comparison  between  the  heat  from  some  artificially  heated 
object  and  that  which  would  be  given  out  from  an  equal  area 
of  the  sun's  face.  Now,  supposing  like  emissive  powers,  if  the 
latter  be  found  the  hotter,  though  we  cannot  tell  what  its 
temperature  absolutely  is,  we  can  at  least  say  that  it  is  greater 
than  that  of  the  thing  with  which  it  is  compared ;  so  that  we 
choose  for  comparison  the  hottest  thing  we  can  find,  on  a 
scale  large  enough  for  the  experiment.  One  observation  of 
my  own  in  this  direction  I  will  permit  myself  to  cite  in  illus- 
tration. 

Perhaps  the  highest  temperature  we  can  get  on  a  large  scale 
in  the  arts  is  that  of  molten  steel  in  the  Bessemer  converter.  As 
many  may  be  as  ignorant  of  what  this  is  as  I  was  before  I  tried 
the  experiment,  I  will  try  to  describe  it. 

The  " converter"  is  an  enormous  iron  pot,  lined  with  fire- 
brick, and  capable  of  holding  thirty  or  forty  thousand  pounds 
of  melted  metal;  and  it  is  swung  on  trunnions,  so  that  it  can 
be  raised  by  an  engine  to  a  vertical  position,  or  lowered  by 
machinery  so  as  to  pour  its  contents  out  into  a  caldron.  First 
the  empty  converter  is  inclined,  and  fifteen  thousand  pounds 
of  fluid  iron  streams  down  into  the  mouth  from  an  adjacent 
furnace  where  it  has  been  melted.  Then  the  engine  lifts  the 
converter  into  an  erect  position,  while  an  air-blast  from  a 
blowing-engine  is  forced  in  at  the  bottom  and  through  the 
liquid  iron,  which  has  combined  with  it  nearly  half  a  ton  of 


{  UNIVERSITY 


THE  SUN'S  ENERGY.  107 

silicon  and  carbon, — materials  which,  with  the  oxygen  of  the 
blast,  create  a  heat  which  leaves  that  of  the  already  molten  iron 
far  behind.  After  some  time  the  converter  is  tipped  forward, 
and  fifteen  hundred  pounds  more  of  melted  iron  is  added  to  that 
already  in  it.  What  the  temperature  of  this  last  is,  may  be 
judged  from  the  fact  that  though  ordinary  melted  iron  is  daz- 
zlingly  bright,  the  melted  metal  in  the  converter  is  so  much 
brighter  still,  that  the  entering  stream  is  dark  brown  by  compar- 
ison, presenting  a  contrast  like  that  of  chocolate  poured  into  a 
white  cup.  The  contents  are  now  no  longer  iron,  but  liquid 
steel,  ready  for  pouring  into  the  caldron ;  and,  looking  from  the 
front  down  into  the  inclined  vessel,  we  see  the  almost  blindingly 
bright  interior  dripping  with  the  drainage  of  the  metal  running 
down  its  side,  so  that  the  circular  mouth,  which  is  twenty-four 
inches  in  diameter,  presents  the  effect  of  a  disk  of  molten  metal 
of  that  size  (were  it  possible  to  maintain  such  a  disk  in  a  vertical 
position).  In  addition,  we  have  the  actual  stream  of  falling 
metal,  which  continues  nearly  a  minute,  and  presents  an  area 
of  some  square  feet.  The  shower  of  scintillations  from  this  cata- 
ract of  what  seems  at  first  "sunlike"  brilliancy,  and  the  area 
whence  such  intense  heat  and  light  are  for  a  brief  time  radiated, 
make  the  spectacle  a  most  striking  one.  (See  Fig.  56.) 

The  "pour"  is  preceded  by  a  shower  of  sparks,  consisting  of 
little  particles  of  molten  steel  which  are  projected  fully  a  hun- 
dred feet  in  the  direction  of  the  open  mouth  of  the  converter. 
In  the  line  of  this  my  apparatus  was  stationed  in  an  open  win- 
dow, at  a  point  where  its  view  could  be  directed  down  into  the 
converter  on  one  side,  and  up  at  the  sun  on  the  other.  This 
apparatus  consisted  of  a  long  photometer-box  with  a  porte-lumiere 
at  one  end.  The  mirror  of  this  reflected  the  sun's  rays  through 
the  box  and  then  on  to  the  pouring  metal,  tracing  their  way  to 
it  by  a  beam  visible  in  the  dusty  air  (Fig.  57).  In  the  path  of 
this  beam  wras  placed  the  measuring  apparatus,  both  for  heat  and 


108 


7V//;   XKW  ASTRONOMY. 


light.  As  the  best  point  of  observation  was  in  the  line  of  the 
blast,  a  shower  of  sparks  was  driven  over  the  instrument  and 
observer  at  every  "pour;"  and  the  rain  of  wet  soot  from  chim- 
neys without,  the  bombardment  from  within,  and  the  moving 
masses  of  red-hot  iron  around,  made  the  experiment  an  al- 
together peculiar  one.  The  apparatus 
was  arranged  in  such  a  way  that  the 
effect  (except  for  the  absorption  of  its 
beams  on  the  way)  was  independent  of 
the  size  or  distance  of  the  sun,  and  de- 
pended on  the  absolute  radiation  there, 
and  was  equivalent,  in  fact,  to  taking  a 
sample  piece  of  the  sun's  face  of  ef/tui/ 
size  with  the  fluid  metal,  bringing  them 
face  to  face,  and  seeing  which  was  the 
hotter  and  brighter.  The  comparison, 
however,  was  unfair  to  the  sun,  because 
its  rays  were  in  reality  partly  absorbed 
by  the  atmosphere  on  the  way,  while 
those  of  the  furnace  were  not.  Under 
these  circumstances  the  heat  from  any 
single  square  foot  of  the  sun's  surface 
was  found  to  be  at  least  eighty-seven 
times  that  from  a  square  foot  of  the 
melted  metal,  while  the  light  from  the 
sun  was  proved  to  be,  foot  for  foot,  over 
five  thousand  times  that  from  the  molten 
steel,  though  the  latter,  separately  con- 
sidered, seemed  to  be  itself,  as  I  have 
said,  of  quite  sunlike  brilliancy. 
We  must  not  conclude  from  this  that  the  tnitftrratitrc,  of  the 
sun  was  five  thousand  times  that  of  the  steel,  but  we  may  be 
certain  that  it  was  at  any  rate  a  great  deal  the  higher  of  the  two. 


TIIR  SUN'S  ENERGY.  Ill 

It  is  probable,  from  all  experiments  made  up  to  tins  date,  that 
the  solar  effective  temperature  is  not  less  than  3,000  nor  more 
than  30,000  degrees  of  the  centigrade  thermometer.  Sir  William 
Siemens,  whose  opinion  on  any  question  as  to  heat  is  entitled  to 
irrcat  respect,  thought  the  lower  value  nearer  the  truth,  but  this 

is  doubtful. 

i 

We  have,  in  all  that  has  preceded,  been  speaking  of  the  sun's 
constitution  and  appearance,  and  have  hardly  entered  on  the 
question  of  its  industrial  relations  to  man.  It  must  be  evident, 
however,  that  if  we  derive,  as  it  is  asserted  we  do,  almost  all 
our  mechanical  power  from  this  solar  heat,  —  if  our  water-wheel 
is  driven  by  rivers  which  the  sun  feeds  by  the  rain  he  sucks  up 
for  them  into  the  clouds,  if  the  coal  is  stored  sun-power,  and  if, 
as  Stevenson  said,  it  really  is  the  sun  which  drives  our  engines, 
though  at  second  hand,  —  there  is  an  immense  fund  of  possible 
mechanical  power  still  coming  to  us  from  him  which  might  be 
economically  utilized.  Leaving  out  of  sight  all  our  more  impor- 
tant relations  to  him  (for,  as  has  been  already  said,  he  is  in  a 
physical  sense  our  creator,  and  he  keeps  us  alive  from  hour  to 
hour),  and  considering  him  only  as  a  possible  servant  to  grind 
our  corn  and  spin  our  flax,  we  find  that  even  in  this  light  there 
are  startling  possibilities  of  profit  in  the  study  of  our  subject. 
From  recent  measures  it  appears  that  from  every  square  yard  of 
the  earth  exposed  perpendicularly  to  the  sun's  rays,  in  the  ab- 
sence of  an  absorbing  atmosphere,  there  could  be  derived  more 
than  one  horse-power,  if  the  heat  were  all  converted  into  this 
use,  and  that  even  on  such  a  little  area  as  the  island  of  Man- 
hattan, or  that  occupied  by  the  city  of  London,  the  noontide  heat 
is  enough,  could  it  all  be  utilized,  to  drive  all  the  steam-engines 
in  the  world.  It  will  not  be  surprising,  then,  to  hear  that  many 
practical  men  are  turning  their  attention  to  this  as  a  source  of 
power,  and  that,  though  it  has  hitherto  cost  more  to  utilize  the 


112  THE  NEW  ASTRONOMY. 

power  than  it  is  worth,  there  is  reason  to  believe  that  some  of 
the  greatest  changes  which  civilization  has  to  bring  may  yet  be 
due  to  such  investigations.  The  visitor  to  the  last  Paris  Expo- 
sition may  remember  an  extraordinary  machine  on  the  grounds 
of  the  Trocadero,  looking  like  a  gigantic  inverted  umbrella 
pointed  sunward.  This  was  the  sun-machine  of  M.  Mouchot, 
consisting  of  a  great  parabolic  reflector,  which  concentrated  the 
heat  on  a  boiler  in  the  focus  and  drove  a  steam-engine  with  it, 
which  was  employed  in  turn  to  work  a  printing-press,  as  our 
engraving  shows  (Fig.  58).  Because  these  constructions  have 
been  hitherto  little  more  than  playthings,  we  are  not  to  think  of 
them  as  useless.  If  toys,  they  are  the  toys  of  the  childhood  of  a 
science  which  is  destined  to  grow,  and  in  its  maturity  to  apply 
this  solar  energy  to  the  use  of  all  mankind. 

Even  now  they  are  beginning  to  pass  into  the  region  of 
practical  utility,  and  in  the  form  of  the  latest  achievement  of 
Mr.  Ericsson's  ever-young  genius  are  ready  for  actual  work  on 
an  economical  scale.  We  present  in  Fig.  59  his  new  actually 
working  solar  engine,  which  there  is  every  reason  to  believe  is 
more  efficient  than  Mouchot's,  and  probably  capable  of  being 
used  with  economical  advantage  in  pumping  water  in  desert 
regions  of  our  own  country.  It  is  pregnant  with  suggestion  of 
the  future,  if  we  consider  the  growing  demand  for  power  in  the 
world,  and  the  fact  that  its  stock  of  coal,  though  vast,  is  strictly 
limited,  in  the  sense  that  when  it  is  gone  we  can  get  absolutely 
no  more.  The  sun  has  been  making  a  little  every  day  for 
millions  of  years,  —  so  little  and  for  so  long,  that  it  is  as  though 
time  had  daily  dropped  a  single  penny  into  the  bank  to  our 
credit  for  untold  ages,  until  an  enormous  fund  had  been  thus 
slowly  accumulated  in  our  favor.  We  are  drawing  on  this  fund 
like  a  prodigal  who  thinks  his  means  endless,  but  the  day  will 
come  when  our  check  will  no  longer  be  honored,  and  what  shall 
we  do  then  I 


FIG.  59.  —  ERICSSON'S   NEW   SOLAR  ENGINE,    NOW  IN  PRACTICAL  USE  IN  NEW  YORK. 


THE  SUN'S  ENERGY.  115 

The  exhaustion  of  some  of  the  coal-beds  is  an  affair  of  the 
immediate  future,  by  comparison  with  the  vast  period  of  time  we 
have  been  speaking  of.  The  English  coal-beds,  it  is  asserted, 
will,  from  present  indications,  be  quite  used  up  in  about  three 
hundred  years  more. 

Three  hundred  years  ago,  the  sun,  looking  down  on  the  Eng- 
land of  our  forefathers,  saw  a  fair  land  of  green  woods  and  quiet 
waters,  a  land  unvexed  with  noisier  machinery  than  the  spinning- 
wheel,  or  the  needles  of  the  "  free  maids  that  weave  their  threads 
with  bones."  Because  of  the  coal  which  has  been  dug  from  its 
soil,  he  sees  it  now  soot-blackened,  furrowed  with  railway- 
cuttings,  covered  with  noisy  manufactories,  filled  with  grimy 
operatives,  while  the  island  shakes  with  the  throb  of  coal-driven 
engines,  and  its  once  quiet  waters  are  churned  by  the  wheels  of 
steamships.  Many  generations  of  the  lives  of  men  have  passed 
to  make  the  England  of  Elizabeth  into  the  England  of  Victoria ; 
but  what  a  moment  this  time  is,  compared  with  the  vast  lapse  of 
ages  during  which  the  coal  was  being  stored  !  What  a  moment 
in  the  life  of  the  "  all-beholding  sun,"  who  in  a  few  hundred 
years  —  his  gift  exhausted  and  the  last  furnace-fire  out  —  may 
send  his  beams  through  rents  in  the  ivy-grown  walls  of  deserted 
factories,  upon  silent  engines  brown  with  rust,  while  the  mill- 
hand  has  gone  to  other  lands,  the  rivers  are  clean  again,  the  har- 
bors show  only  white  sails,  and  England's  "black  country"  is 
green  once  more !  To  America,  too,  such  a  time  may  come, 
though  at  a  greatly  longer  distance. 

Does  this  all  seem  but  the  idlest  fancy?  That  something 
like  it  will  come  to  pass  sooner  or  later,  is  a  most  certain  fact  — 
as  certain  as  any  process  of  Nature  —  if  we  do  not  find  a  new 
source  of  power ;  for  of  the  coal  which  has  supplied  us,  after  a 
certain  time  we  can  get  no  more. 

Future  ages  may  see  the  seat  of  empire  transferred  to  regions 
of  the  earth  now  barren  and  desolated  under  intense  solar  heat, 


116  THE  NEW  ASTRONOMY. 

—  countries  which,  for  that  very  cause,  will  not  improbably 
become  the  seat  of  mechanical  and  thence  of  political  power. 
Whoever  finds  the  way  to  make  industrially  useful  the  vast  sun- 
power  now  wasted  on  the  deserts  of  North  Africa  or  the  shores 
of  the  Red  Sea,  will  effect  a  greater  change  in  men's  affairs  than 
any  conqueror  in  history  has  done ;  for  he  will  once  more  people 
those  waste  places  with  the  life  that  swarmed  there  in  the  best 
days  of  Carthage  and  of  old  Egypt,  but  under  another  civiliza- 
tion, where  man  no  longer  shall  worship  the  sun  as  a  god,  but 
shall  have  learned  to  make  it  his  servant. 


V. 

THE  PLANETS  AND  THE  MOON. 

WHEN  we  look  up  at  the  heavens,  we  see,  if  we  watch 
through  the  night,  the  host  of  stars  rising  in  the  east 
and  passing  above  us  to  sink  in  the  west,  always  at  the  same 
distance  and  in  unchanging  order,  each  seeming  a  point  of  light 
as  feeble  as  the  glow-worm's  shine  in  the  meadow  over  which 
they  are  rising,  each  flickering  as  though  the  evening  wind 
would  blow  it  out.  The  infant  stretches  out  its  hand  to  grasp 
the  Pleiades ;  but  when  the  child  has  become  an  old  man  the 
"  seven  stars"  are  still  there  unchanged,  dim  only  in  his  aged 
sight,  and  proving  themselves  the  enduring  substance,  while  it 
is  his  own  life  which  has  gone,  as  the  shine  of  the  glow-worm  in 
the  night.  They  were  there  just  the  same  a  hundred  generations 
ago,  before  the  Pyramids  were  built ;  and  they  will  tremble  there 
still,  when  the  Pyramids  have  been  worn  down  to  dust  with  the 
blowing  of  the  desert  sand  against  their  granite  sides.  They 
watched  the  earth  grow  fit  for  man  long  before  man  came,  and 
they  will  doubtless  be  shining  on  when  our  poor  human  race 
itself  has  disappeared  from  the  surface  of  this  planet. 

Probably  there  is  no  one  of  us  who  has  not  felt  this  solemn 
sense  of  their  almost  infinite  duration  as  compared  with  his  own 
little  portion  of  time,  and  it  would  be  a  worthy  subject  for  our 
thought  if  we  could  study  them  in  the  light  that  the  New  As- 
tronomy sheds  for  us  on  their  nature.  But  I  must  here  confine 


]18  THE  NEW  ASTJtUXUMY. 

myself  to  the  description  of  but  a  few  of  their  number,  and 
speak,  not  of  the  infinite  multitude  and  variety  of  stars,  each  a 
self-shining  sun,  but  only  of  those  which  move  close  at  hand ; 
for  it  is  not  true  of  quite  all  that  they  keep  at  the  same  distance 
and  order. 

Of  the  whole  celestial  army  Avhich  the  naked  eye  watches, 
there  are  five  stars  which  do  change  their  places  in  the  ranks, 
and  these  change  in  an  irregular  and  capricious  manner,  going 
about  among  the  others,  now  forward  and  now  back,  as  if  lost 
and  wandering  through  the  sky.  These  wanderers  were  long 
since  known  by  distinct  names,  as  Mercury,  Venus,  Mars,  Jupi- 
ter, and  Saturn,  and  believed  to  be  nearer  than  the  others ;  and 
they  are,  in  fact,  companions  to  the  earth  and  fed  like  it  by  the 
warmth  of  our  sun,  and  like  the  moon  are  visible  by  the  sun- 
light which  they  reflect  to  us.  With  the  earliest  use  of  the  tele- 
scope, it  was  found  that  while  the  other  stars  remained  in  it 
mere  points  of  light  as  before,  these  became  magnified  into 
disks  on  which  markings  were  visible,  and  the  markings  have 
been  found  with  our  modern  instruments,  in  one  case  at  least,  to 
take  the  appearance  of  oceans  and  snow-capped  continents  and 
islands.  These,  then,  are  not  uninhabitable  self- shining  suns, 
but  worlds,  vivified  from  the  same  fount  of  energy  that  supplies 
us,  and  the  possible  abode  of  creatures  like  ourselves. 

"  Properly  speaking,"  it  is  said,  "  man  is  the  only  subject  of 
interest  to  man ; "  and  if  we  have  cared  to  study  the  uninhab- 
itable sun  because  all  that  goes  on  there  is  found  to  be  so  inti- 
mately related  to  us,  it  is  surely  a  reasonable  curiosity  which 
prompts  the  question  so  often  heard  as  to  the  presence  of  life  on 
these  neighbor  worlds,  where  it  seems  at  least  not  impossible 
that  life  should  exist.  Even  the  very  little  we  can  say  in  an- 
swer to  this  question  will  always  be  interesting;  but  we  must 
regretfully  admit  at  the  outset  that  it  is  but  little,  and  that  with 
some  planets,  like  Mercury  and  Venus,  the  great  telescopes  of 


UNIVERSITY 


THE  PLANETS  AND    THE  MOON.  121 

modern  times  cannot  do  much  more  than  those  of  Galileo,  with 
which  our  New  Astronomy  had  its  beginning. 

Let  us  leave  these,  then,  and  pass  out  to  the  confines  of  the 
planetary  system,  where  we  may  employ  our  telescopes  to  better 
advantage. 

The  outer  planets,  Neptune  and  Uranus,  remain  pale  disks 
in  the  most  powerful  instruments,  the  first  attended  by  a  single 
moon,  the  second  by  four,  barely  visible ;  and  there  is  so  very 
little  yet  known  about  their  physical  features,  tha,t  we  shall  do 
better  to  give  our  attention  to  one  of  the  most  interesting  objects 
in  the  whole  heavens,  —  the  planet  Saturn,  on  which  we  can  at 
any  rate  see  enough  to  arouse  a  lively  curiosity  to  know  more. 

When  Galileo  first  turned  his  glass  on  Saturn,  he  saw,  as  he 
thought,  that  it  consisted  of  three  spheres  close  together,  the 
middle  one  being  the  largest.  He  was  not  quite  sure  of  the  fact, 
and  was  in  a  dilemma  between  his  desire  to  wait  longer  for 
further  observation,  and  his  fear  that  some  other  observer  might 
announce  the  discovery  if  he  hesitated.  To  combine  these  in- 
compatibilities—  to  announce  it  so  as  to  secure  the  priority,  and 
yet  not  announce  it  till  he  w^as  ready  —  might  seem  to  present 
as  great  a  difficulty  as  the  discovery  itself;  but  Galileo  solved 
this,  as  we  may  remember,  by  writing  it  in  the  sentence,  "  Altis- 
simum  planetam  tergeminum  observavi"  ("I  have  observed  the 
highest  planet  to  be  triple"),  and  then  throwing  it  (in  the 
printer's  phrase)  "  into  pi,"  or  jumbling  the  letters,  which 
made  the  sentence  into  the  monstrous  word 

SMAJSMRMJLMEBOETALEVMJPVNENVGTTAVJRAS, 

and  publishing  this,  which  contained  his  discovery,  but  under 
lock  and  key.  He  had  reason  to  congratulate  himself  on  his 
prudence,  for  within  two  years  two  of  the  supposed  bodies  dis- 
appeared, leaving  only  one.  This  was  in  1612;  and  for  nearly 
fifty  years  Saturn  continued  to  all  astronomers  the  enigma 


122 


THE  NEW  ASTRONOMY. 


which  it  was  to  Galileo,  till  in  1656  it  was  finally  made  clear 
that  it  was  surrounded  by  a  thin  flat  ring,  which  when  seen 
fully  gave  rise  to  the  first  appearance  in  Galileo's  small  tele- 
scope, and  when  seen  edgewise  disappeared  from  its  view  alto- 
gether. '  Everything  in  this  part  of  our  work  depends  on  flie  I 

v 


FIG.    01.  —  THE   EQUATORIAL  TELESCOPE   AT   WASHINGTON. 

power  of  the  telescope  we  employ,  and  in  describing  the  modem 
means  of  observation  we  pass  over  two  centuries  of  slow  ad- 
vance, each  decade  of  which  has  marked  some  progress  in  the 
instrument,  to  one  of  its  completest  types,  in  the  great  equatorial 
at  Washington,  shown  in  Fig.  61. 

The  revolving  dome  above,  the  great  tube  beneath,  its  mas- 
sive piers,  and  all  its  accessories  are  only  means  to  carry  and 


THE  J'LAXKTS  AM)    Till-:   Mun\.  123 

direct  the  great  lens  at  the  further  end,  which  acts  the  part  of 
the  lens  in  our  own  eye,  and  forms  the  image  of  the  thing  to  be 
looked  at.  Galileo's  original  lens  was  a  single  piece  of  glass, 
rather  smaller  than  that  of  our  common  spectacles ;  but  the  lens 
here  is  composed  of  two  pieces,  each  twenty-six  inches  in  diame- 
ter, and  collects  as  much  light  as  a  human  eye  would  do  if  over 
two  feet  across.  But  this  is  useless  if  the  lens  is  not  shaped 
with  such  precision  as  to  send  every  ray  to  its  proper  place 
at  the  eye-piece,  nearly  thirty-five  feet  away ;  and,  in  fact,  the 
shape  given  its  surface  by  the  skilful  hands  of  the  Messrs. 
Clark,  who  made  it,  is  so  exquisitely  exact  that  all  the  light 
of  a  star  gathered  by  this  great  surface  is  packed  at  the  distant 
focus  into  a  circle  very  much  smaller  than  that  made  by  the  dot 
on  this  i,  and  the  same  statement  may  be  made  of  the  great  Lick 
glass,  which  is  three  feet  in  diameter,  —  an  accuracy  we  might 
call  incredible  were  it  not  certain.  It  is  with  instruments  of 
such  accuracy  that  astronomy  now  works,  and  it  is  with  this 
particular  one  that  some  of  the  observations  we  are  going  to 
describe  have  been  made. 

In  all  the  heavens  there  is  no  more  wonderful  object  than 
Saturn,  for  it  preserves  to  us  an  apparent  type  of  the  plan  on 
which  all  the  worlds  were  originally  made.  Let  us  look  at  it 
in  this  study  by  Trouvelot  (Fig.  60).  The  planet,  we  must  re- 
member, is  a  globe  nearly  seventy  thousand  miles  in  diameter, 
and  the  outermost  ring  is  over  one  hundred  and  fifty  thousand 
miles  across,  so  that  the  proportionate  size  of  our  earth  would  be 
over-represented  here  by  a  pea  laid  on  the  engraving.  The 
belts  on  the  globe  show  delicate  tints  of  brown  and  blue,  and 
parts  of  the  ring  are,  as  a  whole,  brighter  than  the  planet ;  but 
this  ring,  as  the  reader  may  see,  consists  of  at  least  three  main 
divisions,  each  itself  containing  separate  features.  First  is  the 
gray  outer  ring,  then  the  middle  one,  and  next  the  curious 
"  crape "  ring,  very  much  darker  than  the  others,  looking  like 


124  THE  NEW  ASTRONOMY. 

a  belt  where  it  crosses  the  planet,  and  apparently  feebly  trans- 
parent, for  the  outline  of  the  globe  has  been  seen  (though  not 
very  distinctly)  through  it.  The  whole  system  of  rings  is  of  the 
most  amazing  thinness,  for  it  is  probably  thinner  in  proportion 
to  its  size  than  the  paper  on  which  this  is  printed  is  to  the  width 
of  the  page;  and  when  it  is  turned  edgewise  to  us,  it  disappears 
to  all  but  the  most  powerful  telescopes,  in  which  it  looks  then 
like  the  thinnest  conceivable  line  of  light,  on  which  the  moons 
have  been  seen  projected,  appearing  like  beads  sliding  along 
a  golden  wire.  The  globe  of  the  planet  casts  on  the  ring  a 
shadow,  which  is  here  shown  as  a  broken  line,  as  though  the 
level  of  the  rings  were  suddenly  disturbed.  At  other  times  (as 
in  a  beautiful  drawing  made  with  the  same  instrument  by  Pro- 
fessor Holden)  the  line  seems  continuous,  though  curved  as 
though  the  middle  of  the  ring  system  were  thicker  than  the 
edge.  The  rotation  of  the  ring  has  been  made  out  by  direct 
observations ;  and  the  whole  is  in  motion  about  the  globe,  —  a 
motion  so  smooth  and  steady  that  there  is  no  flickering  in  the 
shadow  "  where  Saturn's  steadfast  shade  sleeps  on  its  luminous 
ring." 

What  is  it  ?  No  solid  could  hold  together  under  such  condi- 
tions ;  we  can  hardly  admit  the  possibility  of  its  being  a  liquid 
film  extended  in  space ;  and  there  are  difficulties  in  admitting 
it  to  be  gaseous.  But  if  not  a  solid,  a  liquid,  or  a  gas,  again 
what  can  it  be?  It  was  suggested  nearly  two  centuries  ago 
that  the  ring  might  be  composed  of  innumerable  little  bodies 
like  meteorites,  circling  round  the  globe  so  close  together  as  to 
give  the  appearance  we  see,  much  as  a  swarm  of  bees  at  a  dis- 
tance looks  like  a  continuous  cloud ;  and  this  remains  the  most 
plausible  solution  of  what  is  still  in  some  degree  a  mystery. 
Whatever  it  be,  we  see  in  the  ring  the  condition  of  things 
which,  according  to  the  nebular  hypothesis,  once  pertained  to 
all  the  planets  at  a  certain  stage  of  their  formation ;  and  this, 


THE  PLANETS  AND    THE  MOON.  127 

with  the  extraordinary  lightness  of  the  globe  (for  the  whole 
planet  would  float  on  water),  makes  us  look  on  it  as  still  in  the 
formative  stage  of  uncondensed  matter,  where  the  solid  land  as 
yet  is  not,  and  the  foot  could  find  no  resting-place.  Astrology 
figured  Saturn  as  "spiteful  and  cold,  —  an  old  man  melan- 
choly ; "  but  if  we  may  indulge  such  a  speculation,  modern 
astronomy  rather  leads  us  to  think  of  it  as  in  the  infancy  of 
its  life,  with  every  process  of  planetary  growth  still  in  its  future, 
and  separated  by  an  almost  unlimited  stretch  of  years  from  the 
time  when  life  under  the  conditions  in  which  we  know  it  can 
even  begin  to  exist.  ^ 

Like  this  appears  also  the  condition  of  Jupiter  (Fig.  62),  the 
greatest  of  the  planets,  whose  globe,  eighty-eight  thousand 
miles  in  diameter,  turns  so  rapidly  that  the  centrifugal  force 
causes  a  visible  flattening.  The  belts  which  stretch  across  its 
disk  are  of  all  delicate  tints  —  some  pale  blue,  some  of  a  crimson 
lake ;  a  sea-green  patch  has  been  seen,  and  at  intervals  of  late 
years  there  has  been  a  great  oval  red  spot,  which  has  now 
nearly  gone,  and  which  our  engraving  does  not  show.  The 
belts  are  largely,  if  not  wholly,  formed  of  rolling  clouds,  drifting 
and  changing  under  our  eyes,  though  more  rarely  a  feature  like 
the  oval  spot  just  mentioned  will  last  for  years,  an  enduring 
enigma.  The  most  recent  observations  tend  to  make  us  believe 
that  the  equatorial  regions  of  Jupiter,  like  those  of  the  sun, 
make  more  turns  in  a  year  than  the  polar  ones ;  while  the  dark- 
ening toward  the  edge  is  another  sun-like  feature,  though  per- 
haps due  to  a  distinct  cause,  and  this  is  beautifully  brought  out 
when  any  one  of  the  four  rnoons  which  circle  the  planet  passes 
between  us  and  its  face,  an  occurrence  also  represented  in  our 
figure.  The  moon,  as  it  steals  on  the  comparatively  dark  edge, 
shows  us  a  little  circle  of  an  almost  lemon-yellow,  but  the  effect 
of  contrast  grows  less  as  it  approaches  the  centre.  Next  (or 


128  THE  NEW  ASTRONOMY. 

sometimes  before),  the  disk  is  invaded  by  a  small  and  intensely 
black  spot,  the  shadow  of  the  moon,  which  slides  across  the 
planet's  face,  the  transit  lasting  long-  enough  for  us  to  see  that 
the  whole  great  globe,  serving  as  a  background  for  the  spec- 
tacle, has  visibly  revolved  on  its  axis  since  we  began  to  gaze. 
Photography,  in  the  skilful  hands  of  the  late  Professor  Henry 
Draper,  gave  us  reason  to  suspect  the  possibility  that  a  dull 
light  is  sent  to  us  from  parts  of  the  planet's  surface  besides  what 
it  reflects,  as  though  it  were  still  feebly  glowing  like  a  nearly 
extinguished  sun;  and,  on  the  whole,  a  main  interest  of  these 
features  to  us  lies  in  the  presumption  they  create  that  the  giant 
planet  is  not  yet  fit  to  be  the  abode  of  life,  but  is  more  probably 
in  a  condition  like  that  of  our  earth  millions  of  years  since,  in  a 
past  so  remote  that  geology  only  infers  its  existence,  and  long 
before  our  own  race  began  to  be.  That  science,  indeed,  itself 
teaches  us  that  such  all  but  infinite  periods  are  needed  to  pre- 
pare a  planet  for  man's  abode,  that  the  entire  duration  of  his 
race  upon  it  is  probably  brief  in  comparison. 

We  pass  by  the  belt  of  asteroids,  and  over  a  distance  many 
times  greater  than  that  which  separates  the  earth  from  the  sun, 
till  we  approach  our  own  world.  Here,  close  beside  it  as  it 
were,  in  comparison  with  the  enormous  spaces  which  intervene 
between  it  and  Saturn  and  Jupiter,  we  find  a  planet  whose  size 
and  features  are  in  striking  contrast  to  those  of  the  great  globe 
we  have  just  quitted.  It  is  Mars,  which  shines  so  red  and  looks 
so  large  in  the  sky  because  it  is  so  near,  but  whose  diameter 
is  only  about  half  that  of  our  earth.  This  is  indeed  properly  to 
be  called  a  neighbor  world,  but  the  planetary  spaces  are  so  im- 
mense that  this  neighbor  is  at  closest  still  about  thirty-four 
million  miles  away. 

Looking  across  that  great  gulf,  we  see  in  our  engraving 
(Fig.  63)  —  where  we  have  three  successive  views  taken  at  inter- 


Till-:   PLANETS   AXD    THE  MOON. 


129 


vals  of  a  few  hours  —  a  globe  not  marked  by  the  belts  of  Jupiter 
or  Saturn,  but  with  outlines  as  of  continents  and  islands,  which 
pass  in  turn  before  our  eyes  as  it  revolves  in  a  little  over 


twenty-four  and  a  half  of  our  hours,  while  at  either  pole  is  a 
white  spot.  Sir  William  Herschel  was  the  first  to  notice  that 
this  spot  increased  in  size  when  it  was  turned  away  from  the 
sun,  and  diminished  when  the  solar  heat  fell  on  it ;  so  that  we 
have  what  is  almost  proof  that  here  is  ice  (and  consequently 


130  THE  NEW  ASTRONOMY. 

water)  on  another  world.  Then,  as  we  study  more,  we  discern 
forms  which  move  from  day  to  day  on  the  globe  apart  from 
its  rotation,  and  w^e  recognize  in  them  clouds  sweeping  over 
the  surface,  —  not  a  surface  of  still  other  clouds  below, 
but  of  what  we  have  good  reason  to  believe  to  be  land  and 
water. 

By  the  industry  of  numerous  astronomers,  seizing  every 
favorable  opportunity  when  Mars  comes  near,  so  many  of  these 
features  have  been  gathered  that  we  have  been  enabled  to  make 
fairly  complete  maps  of  the  planet,  one  of  which  by  Mr.  Green 
is  here  given  (Fig.  64). 

Here  we  see  the  surface  more  diversified  than  that  of  our 
earth,  while  the  oceans  are  long,  narrow,  canal-like  seas,  which 
everywhere  invade  the  land,  so  that  on  Mars  one  could  travel 
almost  everywhere  by  water.  These  canals  seem  also  in  some 
cases  to  exist  in  pairs  or  to  be  remarkably  duplicated.  The 
spectroscope  indicates  water-vapor  in  the  Martial  atmosphere, 
and  some  of  the  continents,  like  "  Lockyer  Land,"  are  some- 
times seen  white,  as  though  covered  with  ice :  while  one  island 
(marked  on  our  map  as  Hall  Island)  has  been  seen  so  frequently 
thus,  that  it  is  very  probable  that  here  some  mountain  or  table- 
land rises  into  the  region  of  perpetual  snow. 

The  cause  of  the  red  color  of  Mars  has  never  been  satisfac- 
torily ascertained.  Its  atmosphere  does  not  appear  to  be  dark 
enough  to  produce  such  an  effect,  and  perhaps  as  probable  an 
explanation  as  any  is  one  the  suggestion  of  which  is  a  little 
startling  at  first.  It  is  that  vegetation  on  Mars  may  be  red  in- 
stead of  green  !  There  is  no  intrinsic  improbability  in  the  idea, 
for  we  are  even  to-day  unprepared  to  say  with  any  certain ty 
why  vegetation  is  green  here,  and  it  is  quite  easy  to  conceive  of 
atmospheric  conditions  which  would  make  red  the  best  absorber 
of  the  solar  heat.  Here,  then,  we  find  a  planet  on  which  we 
obtain  many  of  the  conditions  of  life  which  we  know  ourselves, 


THE  PLANETS  AND    THE  MOON.  131 

and  here,  if  anywhere  in  the  system,  we  may  allowably  inquire 
for  evidence  of  the  presence  of  something  like  our  own  race; 
but  though  we  may  indulge  in  supposition,  there  is  unfortu- 
nately no  prospect  that  with  any  conceivable  improvement  in 
our  telescopes  we  shall  ever  obtain  anything  like  certainty.  We 
cannot  assert  that  there  are  any  bounds  to  man's  invention,  or 
that  science  may  not,  by  some  means  as  unknown  to  us  as  the 
spectroscope  was  to  our  grandfathers,  achieve  what  now  seems 
impossible ;  but  to  our  present  knowledge  no  such  means  exist, 
though  we  are  not  forbidden  to  look  at  the  ruddy  planet  with 
the  feeling  that  it  may  hold  possibilities  more  interesting  to  our 
humanity  than  all  the  wonders  of  the  sun,  and  all  the  unin- 
habitable immensities  of  his  other  worlds. 

Before  we  leave  Mars,  we  may  recall  to  the  reader's  memory 
the  extraordinary  verification  of  a  statement  made  about  it  more 
than  a  hundred  years  ago.  We  shall  have  for  a  moment  to 
leave  the  paths  of  science  for  those  of  pure  fiction,  for  the  words 
we  are  going  to  quote  are  those  of  no  less  a  person  than  our  old 
friend  Captain  Gulliver,  who,  after  his  adventures  with  the  Lil- 
liputians, went  to  a  flying  island  inhabited  largely  by  astrono- 
mers. If  the  reader  will  take  down  his  copy  of  Swift,  he  will 
find  in  this  voyage  of  Gulliver's  to  Laputa  the  following  imagi- 
nary description  of  what  its  imaginary  astronomers  saw :  — 

"  They  have  likewise  discovered  two  lesser  stars  or  satellites  which 
revolve  about  Mars,  whereof  the  innermost  is  distant  from  the  centre 
of  the  primary  planet  exactly  three  of  its  diameters,  and  the  outermost 
five ;  the  former  revolves  in  the  space  of  ten  hours,  and  the  latter  in 
twenty-one  and  a  half." 

Now,  compare  this  passage,  which  was  published  in  the  year 
1727,  with  the  announcement  in  the  scientific  journals  of  Au- 
gust, 1877  (a  hundred  and  fifty  years  after),  that  two  moons 
did  exist,  and  had  just  been  discovered  by  Professor  Hall,  of 


132  THE   XEW 

Washing-ton,  with  the  great  telescope  of  which  a  drawing-  has 
been  already  given.  The  resemblance  does  not  end  even  here, 
for  Swift  was  right  also  in  describing  them  as  very  near  the 
planet  and  with  very  short  periods,  the  actual  distances  being 
about  one  and  a  half  and  seven  diameters,  and  the  actual  times 
about  eight  and  thirty  hours  respectively,  —  distances  and  periods 
which,  if  not  exactly  those  of  Swift's  description,  agree  with  it 
in  being  less  than  any  before  known  in  the  solar  system.  It  is 
certain  that  there  could  not  have  been  the  smallest  ground  for 
a  suspicion  of  their  existence  when  "Gulliver's  Travels7'  was 
written,  and  the  coincidence  —  which  is  a  pure  coincidence - 
certainly  approaches  the  miraculous.  We  can  no  longer,  then, 
properly  speak  of  "  the  snowy  poles  of  moonless  Mars,"  though 
it  does  still  remain  moonless  to  all  but  the  most  powerful  tele- 
scopes in  the  world,  for  these  bodies  are  the  very  smallest 
known  in  the  system.  They  present  no  visible  disks  to  meas- 
ure, but  look  like  the  faintest  of  points  of  light,  and  their  size 
is  only  to  be  guessed  at  from  their  brightness.  Professor  Pick- 
ering has  carried  on  an  interesting  investigation  of  them.  IT  is 
method  depended  in  part  on  getting  holes  of  such  smallness 
made  in  a  plate  of  metal  that  the  light  coming  through  them 
would  be  comparable  with  that  of  the  Martial  moons  in  the 
telescope.  It  was  found  almost  impossible  to  command  the  skill 
to  make  these  holes  small  enough,  though  one  of  the  artists  em- 
ployed had  already  distinguished  himself  by  drilling  a  hole 
through  a  fine  cambric  needle  lengthwise,  so  as  to  make  a  tiny 
steel  tube  of  it.  When  the  difficulty  was  at  last  overcome,  the 
satellites  were  found  to  be  less  than  ten  miles  in  diameter,  and 
a  just  impression  both  of  their  apparent  size  and  light  may  be 
gathered  from  the  statement  that  cither  roughly  corresponds  to 
that  which  would  be  given  by  a  human  hand  held  up  at  Wash- 
ington, and  viewed  from  Boston,  Massachusetts,  a  distance  of 
four  hundred  miles. 


THE  PLAXKTS   AX1)    TUK  MOON.  133 

We  approach  now  the  only  planet  in  which  man  is  certainly 
known  to  exist,  and  which  ought  to  have  an  interest  for  us  supe- 
rior to  any  which  we  have  yet  seen,  for  it  is  our  own.  We  are 
voyagers  on  it  through  space,  it  has  been  said,  as  passengers  on  a 
ship,  and  many  of  us  have  never  thought  of  any  part  of  the  vessel 
but  the  cabin  where  we  are  quartered.  Some  curious  passengers 
(these  are  the  geographers)  have  visited  the  steerage,  and  some 
(the  geologists)  have  looked  under  the  hatches,  and  yet  it  re- 
mains true  that  those  in  one  part  of  our  vessel  know  little,  even 
now,  of  their  fellow-voyagers  in  another.  How  much  less,  then, 
do  most  of  us  know  of  the  ship  itself,  for  we  were  all  born  on  it, 
and  have  never  once  been  off  it  to  view  it  from  the  outside ! 

No  world  comes  so  near  us  in  the  aerial  ocean  as  the  moon ; 
and  if  we  desire  to  view  our  own  earth  as  a  planet,  we  may 
put  ourselves  in  fancy  in  the  place  of  a  lunar  observer.  "Is 
it  inhabited ! "  would  probably  be  one  of  the  first  questions 
which  he  would  ask,  if  he  had  the  same  interest  in  us  that  we 
have  in  him ;  and  the  answer  to  this  would  call  out  all  the 
powers  of  the  best  telescopes  such  as  we  possess. 

An  old  author,  Fontenelle,  has  put  in  the  mouth  of  an  imagi- 
nary spectator  a  lively  description  of  what  would  be  visible  in 
twenty -four  hours  to  one  looking  down  on  the  earth  as  it  turned 
round  beneath  him.  "  I  see  passing  under  my  eyes,"  he  says, 
"all  sorts  of  faces, — white  and  black  and  olive  and  brown. 
Now  it's  hats,  and  now  turbans,  now  long  locks  and  then  shaven 
crowns ;  now  come  cities  with  steeples,  next  more  with  tall,  cres- 
cent-capped minarets,  then  others  with  porcelain  towers ;  now 
great  desolate  lands,  now  great  oceans,  then  dreadful  deserts,  — 
in  short,  all  the  infinite  variety  the  earth's  surface  bears."  The 
truth  is,  however,  that,  looking  at  the  earth  from  the  moon,  the 
largest  moving  animal,  the  whale  or  the  elephant,  would  be  ut- 
terly beyond  our  ken ;  and  it  is  questionable  whether  the  largest 
ship  on  the  ocean  would  be  visible,  for  the  popular  idea  as  to 


134  THE  NEW  ASTRONOMY. 

the  magnifying  power  of  great  telescopes  is  exaggerated.  It  is 
probable  that  under  any  but  extraordinary  circumstances  our 
lunar  observer,  with  our  best  telescopes,  could  not  bring  the 
earth  within  less  than  an  apparent  distance  of  five  hundred 
miles ;  and  the  reader  may  judge  how  large  a  moving  object 
must  be  to  be  seen,  much  less  recognized,  by  the  naked  eye 
at  such  a  distance. 

Of  course,  a  chief  interest  of  the  supposition  we  are  making- 
lies  in  the  fact  that  it  will  give  us  a  measure  of  our  own  ability 
to  discover  evidences  of  life  in  the  moon,  if  there  are  any  such 
as  exist  here ;  and  in  this  point  of  view  it  is  worth  while  to 
repeat,  that  scarcely  any  temporary  phenomenon  due  to  human 
action  could  be  even  telescopically  visible  from  the  moon  under 
the  most  favoring  circumstances.  An  army  such  as  Napoleon 
led  to  Russia  might  conceivably  be  visible  if  it  moved  in  a  dark 
solid  column  across  the  snow.  It  is  barely  possible  that  such 
a  vessel  as  one  of  the  largest  ocean  steamships  might  be  seen, 
under  very  favorable  circumstances,  as  a  moving  dot ;  and  it  is 
even  quite  probable  that  such  a  conflagration  as  the  great  fire  of 
Chicago  would  be  visible  in  the  lunar  telescope,  as  something 
like  a  reddish  star  on  the  night  side  of  our  planet ;  but  this  is 
all  in  this  sort  that  could  be  discerned. 

By  making  minute  maps,  or,  still  better,  photographs,  and 
comparing  one  year  with  another,  much  however  might  have 
been  done  by  our  lunar  observer  during  this  century.  In  its 
beginning,  in  comparison  to  the  vast  forests  which  then  covered 
the  North  American  continent,  the  cultivated  fields  along  its 
eastern  seaboard  would  have  looked  to  him  like  a  golden  fringe 
bordering  a  broad  mantle  of  green ;  but  now  he  would  see  that 
the  golden  fringe  has  encroached  upon  the  green  farther  back 
than  the  Mississippi,  and  he  would  gather  his  best  evidence 
of  change  from  the  fact  (surely  a  noteworthy  one)  that  the 
people  of  the  United  States  have  altered  the  features  of  the 


THE  PLANETS  AND    THE  MOON.  135 

world  during  the  present  century  to  a  degree  visible  in  another 
planet ! 

Our  observer  would  probably  be  struck  by  the  moving  pan- 
orama of  forests,  lakes,  continents,  islands,  and  oceans,  succes- 
sively gliding  through  the  field  of  view  of  his  telescope  as  the 
earth  revolved ;  but,  travelling  along  beside  it  on  his  lunar 
station,  he  would  hardly  appreciate  its  actual  flight  through 
space,  which  is  an  easy  thing  to  describe  in  figures,  and  a  hard 
one  to  conceive.  If  we  look  up  at  the  clock,  and  as  we  watch 
the  pendulum  recall  that  we  have  moved  about  nineteen  miles 
at  every  beat,  or  in  less  than  three  minutes,  over  a  distance 
greater  than  that  which  divides  New  York  from  Liverpool,  we 
still  probably  but  very  imperfectly  realize  the  fact  that  (dropping 
all  metaphor)  the  earth  is  really  a  great  projectile,  heavier  than 
the  heaviest  of  her  surface  rocks,  and  traversing  space  with  a 
velocity  of  over  sixty  times  that  of  the  cannon-ball.  Even  the 
firing  of  a  great  gun  with  a  ball  weighing  one  or  two  hundred 
pounds  is,  to  the  novice  at  least,  a  striking  spectacle.  The  mas- 
sive iron  sphere  is  hoisted  into  the  gun,  the  discharge  comes,  the 
ground  trembles,  and,  as  it  seems,  almost  in  the  same  instant, 
a  jet  rises  where  the  ball  has  touched  the  water  far  away. 
The  impression  of  immense  velocity  and  of  a  resistless  capacity 
of  destruction  in  that  flying  mass  is  irresistible,  and  justifiable 
too :  but  what  is  this  ball  to  that  of  the  earth,  which  is  a  globe 
counting  eight  thousand  miles  in  diameter,  and  weighing  about 
six  thousand  millions  of  millions  of  millions  of  tons ;  which,  if  our 
cannon-ball  were  flying  ahead  a  mile  in  advance  of  its  track, 
would  overtake  it  in  less  than  the  tenth  part  of  a  second ;  and 
which  carries  such  a  potency  of  latent  destruction  and  death  in 
this  motion,  that  if  it  were  possible  instantly  to  arrest  it,  then, 
in  that  instant,  "  earth  and  all  which  it  inherits  would  dissolve  " 
and  pass  away  in  vapor! 

Our  turning  sphere  is  moving  through  what  seems  to  be  all 


136  THE  NEW  ASTRONOMY. 

but  an  infinite  void,  peopled  only  by  wandering  meteorites,  and 
where  warmth  from  any  other  source  than  the  sun  can  scarcely 
be  said  to  exist ;  for  it  is  important  to  observe  that  whether  the 
interior  be  molten  or  not,  we  get  next  to  no  heat  from  it.  The 
cold  of  outer  space  can  only  be  estimated  in  view  of  recent 
observations  as  at  least  four  hundred  degrees  Fahrenheit  below 
zero  (mercury  freezes  at  thirty-nine  degrees  below),  and  it  is  the 
sun  which  makes  up  the  difference  of  all  these  lacking  hundreds 
of  degrees  to  us,  but  indirectly,  and  not  in  the  way  that  wre 
might  naturally  think,  and  have  till  very  lately  thought;  for 
our  atmosphere  has  a  great  deal  to  do  with  it  beside  the  direct 
solar  rays,  allowing  more  to  come  in  than  to  go  out,  until 
the  temperature  rises  very  much  higher  than  it  would  were 
there  no  air  here.  Thus,  since  it  is  this  power  in  the  atmosphere 
of  storing  the  heat  which  makes  us  live,  no  less  than  the  sun's 
rays  themselves,  we  see  how  the  temperature  of  a  planet  may 
depend  on  considerations  quite  beside  its  distance  from  the  sun; 
and  when  we  discuss  the  possibility  of  life  in  other  worlds,  we 
shall  do  well  to  remember  that  Saturn  may  be  possibly  a  warm 
world,  and  Mercury  conceivably  a  cold  one. 

We  used  to  be  told  that  this  atmosphere  extended  forty -five 
miles  above  us,  but  later  observation  proves  its  existence  at  a 
height  of  many  times  this ;  and  a  remarkable  speculation,  which 
Dr.  Hunt  strengthens  with  the  great  name  of  Newton,  even 
contemplates  it  as  extending  in  ever-increasing  tenuity  until  it 
touches  and  merges  in  the  atmosphere  of  other  worlds. 

But  if  we  begin  to  talk  of  things  new  and  old  which  interest 
us  in  our  earth  as  a  planet,  it  is  hard  to  make  an  end.  Still  we 
may  observe  that  it  is  the  very  familiarity  of  some  of  these 
which  hinders  us  from  seeing  them  as  the  wonders  they  really 
are.  How  has  this  familiarity,  for  instance,  made  commonplace 
to  us  not  only  the  wonderful  fact  that  the  fields  and  forests,  and 
the  apparently  endless  plain  of  earth  and  ocean,  are  really  parts 


FIG.    65. —THE   MOON. 
(FROM    A    PHOTOGRAPH    BY    L.    M.    RUTHERFURU,    1873,    PUBLISHED    BY   O.    G.    MASON.) 


THE  PLANETS  AND    THE  MOON.  139 

of  a  great  globe  which  is  turning  round  (for  this  rotation  we 
all  are  familiar  with),  but  the  less  appreciated  miracle  that  we 
are  all  being  hurled  through  space  with  an  immensely  greater 
speed  than  that  of  the  rotation  itself.  It  needs  the  vision  of  a 
poet  to  see  this  daily  miracle  with  new  eyes ;  and  a  great  poet 
has  described  it  for  us,  in  words  which  may  vivify  our  scientific 
conception.  Let  us  recall  the  prologue  to  "  Faust,"  where  the 
archangels  are  praising  the  works  of  the  Lord,  and  looking  at 
the  earth,  not  as  we  see  it,  but  down  on  it,  from  heaven,  as  it 
passes  by,  and  notice  that  it  is  precisely  this  miraculous  swift- 
ness, so  insensible  to  us,  which  calls  out  an  angel's  wonder. 

11  And  swift  and  swift  beyond  conceiving 
The  splendor  of  the  world  goes  round, 
Day's  Eden-brightness  still  relieving 
The  awful  Night's  intense  profound. 
The  ocean  tides  in  foam  are  breaking, 
Against  the  rocks'  deep  bases  hurled, 
And  both,  the  spheric  race  partaking, 
Eternal,  swift,  are  onward  whirled."1 

So,  indeed,  might  an  angel  see  it  and  describe  it ! 

We  may  have  been  already  led  to  infer  that  there  is  a  kind 
of  evolution  in  the  planets'  life,  which  we  may  compare,  by  a 
not  wholly  fanciful  analogy,  to  ours ;  for  we  have  seen  worlds 
growing  into  conditions  which  may  fit  them  for  habitability, 
and  again  other  worlds  where  we  may  surmise,  or  may  know, 
that  life  has  come.  To  learn  of  at  least  one  which  has  completed 
the  analogy,  by  passing  beyond  this  term  to  that  where  all  life 
has  ceased,  we  need  only  look  on  the  moon. 

The  study  of  the  moon's  surface  has  been  continued  now 
from  the  time  of  Galileo,  and  of  late  years  a  whole  class  of 
competent  observers  has  been  devoted  to  it,  so  that  astronomers 
engaged  in  other  branches  have  often er  looked  on  this  as  a  field 

1  Bayard  Taylor's  translation. 


140  THE  NEW  ASTRONOMY. 

for  occasional  hours  of  recreation  with  the  telescope  than  made 
it  a  constant  study.  I  can  recall  one  or  two  such  hours  in  earlier 
observing  days,  when,  seated  alone  under  the  overarching  iron 
dome,  the  world  below  shut  out,  and  the  world  above  opened, 
the  silence  disturbed  by  no  sound  but  the  beating  of  the  equa- 
torial clock,  and  the  great  telescope  itself  directed  to  some  hill 
or  valley  of  the  moon,  I  have  been  so  lost  in  gazing  that  it 
seemed  as  though  a  look  through  this,  the  real  magic  tube,  had 
indeed  transported  me  to  the  surface  of  that  strange  alien  world. 
Fortunately  for  us,  the  same  spectacle  has  impressed  others  with 
more  time  to  devote  to  it  and  more  ability  to  render  it,  so  that 
we  not  only  have  most  elaborate  maps  of  the  moon  for  the  pro- 
fessional astronomer,  but  abundance  of  paintings,  drawings,  and 
models,  which  reproduce  the  appearance  of  its  surface  as  seen 
in  powerful  telescopes.  None  of  the  latter  class  deserves  more 
attention  than  the  beautiful  studies  of  Messrs.  Nasmyth  and 
Carpenter,  who  prepared  at  great  labor  very  elaborate  and,  in 
general,  very  faithful  models  of  parts  of  its  surface,  and  then 
had  them  photographed  under  the  same  illumination  which  fell 
on  the  original ;  and  I  wish  to  acknowledge  here  the  special 
indebtedness  of  this  part  of  what  I  have  to  lay  before  the 
reader  to  their  work,  from  which  the  following  illustrations  are 
chiefly  taken. 

Let  us  remember  that  the  moon  is  a  little  over  twenty-one 
hundred  miles  in  diameter ;  that  it  weighs,  bulk  for  bulk,  about 
two-thirds  what  the  earth  does,  so  that,  in  consequence  of  this 
and  its  smaller  size,  its  total  weight  is  only  about  one-eightieth 
of  that  of  our  globe  ;  and  that,  the  force  of  gravity  at  its  surface 
being  only  one-sixth  what  it  is  here,  eruptive  explosions  can 
send  their  products  higher  than  in  our  volcanoes.  Its  area  is 
between  four  and  five  times  that  of  the  United  States,  and  its 
average  distance  is  a  little  less  than  two  hundred  and  forty 
thousand  miles. 


FIG.   66.  —  THE   FULL  MOON. 


THE  PLANETS  AND    THE  MOON.  143 

This  is  very  little  in  comparison  with  the  great  spaces  we 
have  been  traversing  in  imagination ;  but  it  is  absolutely  very 
large,  and  across  it  the  valleys  and  mountains  of  this  our  nearest 
neighbor  disappear,  and  present  to  the  naked  eye  only  the  vague 
lights  and  shades  known  to  us  from  childhood  as  "  the  man  in 
the  moon,"  and  which  were  the  puzzle  of  the  ancient  philos- 
ophers, who  often  explained  them  as  reflections  of  the  earth 
itself,  sent  back  to  us  from  the  moon  as  from  a  mirror.  It,  at 
any  rate,  shows  that  the  moon  always  turns  the  same  face  toward 
us,  since  we  always  see  the  same  "man,"  and  that  there  must 
be  a  back  to  the  moon  which  we  never  behold  at  all ;  and,  in 
fact,  nearly  half  of  this  planet  does  remain  forever  hidden  from 
human  observation. 

The  "  man  in  the  moon  "  disappears  when  we  are  looking  in 
a  telescope,  because  we  are  then  brought  so  near  to  details  that 
the  general  features  are  lost ;  but  he  can  be  seen  in  any  photo- 
graph of  the  full  moon  by  viewing  it  at  a  sufficient  distance,  and 
making  allowance  for  the  fact  that  the  contrasts  of  light  and 
shade  appear  stronger  in  the  photograph  than  they  are  in  reality. 
If  the  small  full  moon  given  in  Fig.  66,  for  instance,  be  looked  at 
from  across  a  room,  the  naked-eye  view  will  be  recovered,  and 
its  connection  with  the  telescopic  ones  better  made  out.  The 
best  time  for  viewing  the  moon,  however,  is  not  at  the  full, 
but  at  the  close  of  the  first  quarter;  for  then  we  see,  as  in 
this  beautiful  photograph  (Fig.  65)  by  Mr.  Rutherfurd,  that 
the  sunlight,  falling  slantingly  on  it,  casts  shadows  which  bring 
out  all  the  details  so  that  we  can  distinguish  many  of  them 
even  here,  —  this  photograph,  though  much  reduced,  giving  the 
reader  a  better  view  than  Galileo  obtained  with  his  most  power- 
ful telescope.  The  large  gray  expanse  in  the  lower  part  is  the 
Mare  Serenitatis,  that  on  the  left  the  Mare  Crisium,  and  so  on ; 
these  "  seas/'  as  they  were  called  by  the  old  observers,  being  no 
seas  at  all  in  reality,  but  extended  plains  which  reflect  less  light 


144  THE  NEW  ASTltOXOMY. 

than  other  portions,  and  which  with  higher  powers  show  an 
irregular  surface.  Most  of  the  names  of  the  main  features  of 
the  lunar  surface  were  bestowed  by  the  earlier  observers  in  the 
infancy  of  the  telescope,  when  her  orb 

"Through  optic  glass  the  Tuscan  artist  'viewed7 
At  evening  from  the  top  of  Fiesole 
Or  in  Valdamo.  to  descry  new  lauds, 
Rivers,  or  mountains  in  her  spotty  globe." 

Mountains  there  are,  like  the  chain  of  the  lunar  Apennines, 
which  the  reader  sees  a  little  below  the  middle  of  the  moon,  and 
to  the  right  of  the  Mare  Serenitatis,  and  where  a  good  telescope 
will  show  several  thousand  distinct  summits.  Apart  from  the 
mountain  chains,  however,  the  whole  surface  is  visibly  pitted 
with  shallow,  crater-like  cavities,  which  vary  from  over  a  hun- 
dred miles  in  diameter  to  a  few  hundred  yards  or  less,  and 
which,  we  shall  see  later,  are  smaller  sunken  plains  walled 
about  with  mountains  or  hills. 

One  of  the  most  remarkable,  of  these  is  Tyelio,  here  seen  on 
the  photograph  of  the  full  moon  (Fig.  66),  from  which  radiating 
streaks  go  in  all  directions  over  the  lunar  surface.  These  streaks 
are  a;  feature  peculiar  to  the  moon  (at  least  we  know  of  nothing 
to  which  they  can  be  compared  on  the  earth),  for  they  run 
through  mountain  and  valley  for  hundreds  of  miles  without  any 
apparent  reference  to  the  obstacles  in  their  way,  and  it  is  clear 
that  the  cause  is  a  deep-seated  one.  This  cause  is  believed  by 
our  authors  to  be  the  fact  that  the  moon  was  once  a  liquid  sphere 
over  which  a  hard  crust  formed,  and  that  in  subsequent  time  the 
expansion  of  the  interior  before  solidification  cracked  the  shell  as 
we  see.  The  annexed  figure  (Fig.  67)  is  furnished  by  them  to 
illustrate  their  theory,  and  to  show  the  effects  of  what  they 
believe  to  be  an  analogous  experiment,  in  minimis,  to  what  Na- 
ture has  performed  on  the  grandest  scale ;  for  the  photograph 
shows  a  glass  globe  actually  cracked  by  the  expansion  of  an 


FIG.  67.  —  GLASS  GLOBE,  CRACKED. 


10 


THE  PLANETS  AND    THE  MOON.  147 

enclosed  fluid  (in  this  case  water),  and  the  resemblance  of  the 
model  to  the  photograph  of  the  full  •moon  on  page  141  is 
certainly  a  very  interesting  one. 

We  are  able  to  see  from  this,  and  from  the  multitude  of 
craters  shown  even  on  the  general  view,  where  the  whole  face 
of  our  satellite  is  pit-marked,  that  eruptive  action  has  been  more 
prominent  on  the  moon  in  ages  past  than  on  our  own  planet, 
and  we  are  partly  prepared  for  what  we  see  when  we  begin  to 
studv  it  in  detail. 

«/ 

We  may  select  almost  any  part  of  the  moon's  surface  for  this 
nearer  view,  with  the  certainty  of  finding  something  interesting. 
Let  us  choose,  for  instance,  on  the  photograph  of  the  half-full 
moon  (Fig.  65),  the  point  near  the  lower  part  of  the  Terminator 
(as  the  line  dividing  light  from  darkness  is  called)  where  a  minute 
sickle  of  light  seems  to  invade  the  darkness,  and  let  us  apply  in 
imagination  the  power  of  a  large  telescope  to  it.  We  are  brought 
at  once  considerably  within  a  thousand  miles  of  the  surface, 
over  which  we  seem  to  be  suspended,  everything  lying  directly 
beneath  us  as  in  a  bird's-eye  view,  and  what  we  see  is  the 
remarkable  scene  shown  in  Fig.  68. 

We  have  before  us  such  a  wealth  of  detail  that  the  only  trouble 
is  to  choose  what  to  speak  of  where  every  point  has  something  to 
demand  attention,  and  we  can  only  give  here  the  briefest  refer- 
ence to  the  principal  features.  The  most  prominent  of  these  is 
the  great  crater  "  Plato,"  which  lies  in  the  lower  right-hand  part 
of  the  cut.  It  will  give  the  reader  an  idea  of  the  scale  of  things 
to  state  that  the  diameter  of  its  ring  is  about  seventy  miles ;  so 
that  he  will  readily  understand  that  the  mountains  surrounding- 
it  may  average  five  to  six  thousand  feet  in  height,  as  they  do. 
The  sun  is  shining  from  the  left,  and,  being  low,  casts  long 
shadows,  so  that  the  real  forms  of  the  mountains  on  one  side 
are  beautifully  indicated  by  these  shadows,  where  they  fall  on 
the  floor  of  the  crater.  In  the  lower  part  of  the  mountain  wall 


148  THE  NEW  ASTRONOMY. 

there  has  been  a  land-slide,  as  we  see  by  the  fragments  that 
have  rolled  down  into  the  plain,  and  of  which  a  trace  can  be 
observed  in  our  engraving.  The  whole  is  quite  unlike  most 
terrestrial  craters,  however,  not  only  in  its  enormous  size,  but 
in  its  proportions;  for  the  floor  is  not  precipitous,  but  flat,  or 
partaking  of  the  general  curvature  of  the  lunar  surface,  which 
it  sinks  but  little  below.  I  have  watched  with  interest  in  the 
telescope  streaks  and  shades  on  the  floor  of  Plato,  not  shown  in 
our  cut ;  for  here  some  have  suspected  evidences  of  change,  and 
fancied  a  faint  greenish  tint,  as  if  due  to  vegetation,  but  it  is 
probably  fancy  only.  Notice  the  number  of  small  craters 
around  the  big  one,  and  everywhere  on  the  plate,  and  then 
look  at  the  amazingly  rugged  and  tumbled  mountain  heaps  on 
the  left  (the  lunar  Alps),  cut  directly  through  by  a  great  val- 
ley (the  valley  of  the  Alps),  which  is  at  the  bottom  about  six 
miles  wide  and  extraordinarily  flat, — flatter  and  smoother  even 
than  our  engraving  shows  it,  and  looking  as  though  a  great 
engineering  work,  rather  than  an  operation  of  Nature,  were  in 
question.  Above  this  the  mountain  shadows  are  cast  upon  a 
wide  plain,  in  which  are  both  depressed  pits  with  little  mountain 
(or  rather  hill)  rings  about  them,  and  extraordinary  peaks,  one 
of  which,  Pico  (above  the  great  crater),  starts  up  abruptly  to 
the  height  of  eight  thousand  feet,  a  lunar  Matterhorn. 

If  Mars  were  as  near  as  the  moon,  we  should  see  with  the 
naked  eye  clouds  passing  over  its  face ;  and  that  we  never  do 
see  these  on  the  moon,  even  with  the  telescope,  is  itself  a  proof 
that  none  exist  there.  Now,  this  absence  of  clouds,  or  indeed 
of  any  evidence  of  moisture,  is  confirmed  by  every  one  of  the 
nearer  views  like  those  we  are  here  getting.  We  might  return 
to  this  region  with  the  telescope  every  month  of  our  lives  with- 
out finding  one  indication  of  vapor,  of  moisture,  or  even  of  air: 
and  from  a  summit  like  Pico,  could  we  ascend  it,  we  should 
look  out  on  a  scene  of  such  absolute  desolation  as  probably  no 


•• 


THE  PLANETS  AND    THE  MOON.  151 

earthly  view  could  parallel.  If,  as  is  conceivable,  these  plains 
were  once  covered  with  verdure,  and  the  abode  of  living  crea- 
tures, verdure  and  life  exist  here  110  longer,  and  over  all  must 
be  the  silence  of  universal  death.  But  we  must  leave  it  for 
another  scene. 

South  of  Plato  extends  for  many  hundred  miles  a  great  plain, 
which  from  its  smoothness  was  thought  by  the  ancient  observers 
to  be  water,  and  was  named  by  them  the  "  Imbrian  Sea,"  and 
this  is  bounded  on  the  south  and  west  by  a  range  of  mountains 
—  the  "lunar  Apennines"  (Fig.  69)  —  which  are  the  most  strik- 
ing on  our  satellite.  They  are  visible  even  with  a  spy-glass, 
looking  then  like  bread-crumbs  ranged  upon  a  cloth,  while  with 
a  greater  power  they  grow  larger  and  at  the  same  time  more 
chaotic.  As  we  approach  nearer,  we  see  that  they  rise  with  a 
comparatively  gradual  slope,  to  fall  abruptly,  in  a  chain  of 
precipices  that  may  well  be  called  tremendous,  down  to  the 
plain  below,  across  which  their  shadows  are  cast.  Near  their 
bases  are  some  great  craters  of  a  somewhat  different  type  from 
Plato,  and  our  illustration  represents  an  enlarged  view  of  a 
part  of  this  Apennine  chain,  of  the  great  crater  Archimedes, 
and  of  its  companions  Aristillus  and  Autolycus. 

Our  engraving  will  tell,  more  than  any  description,  of  the 
contrast  of  the  tumbled  mountain  peaks  with  the  level  plain 
from  which  they  spring,  —  a  contrast  for  wrhich  we  have  scarcely 
a  terrestrial  parallel,  though  the  rise  of  the  Alps  from  the  plains 
of  Lombardy  may  suggest  an  inadequate  one  The  Sierra 
Nevadas  of  California  climb  slowly  up  from  the  coast  side,  to 
descend  in  great  precipices  on  the  east,  somewhat  like  this ;  but 
the  country  at  their  feet  is  irregular  and  broken,  and  their 
highest  summits  do  not  equal  those  before  us,  which  rise  to 
seventeen  or  eighteen  thousand  feet,  and  from  one  of  which 
we  should  look  out  over  such  a  scene  of  desolation  as  we 
can  only  imperfectly  picture  to  ourselves  from  any  expe- 


152  THE  NEW  ASTRONOMY. 

Hence  of  a  terrestrial  desert.  The  curvature  of  the  moon's  sur- 
face is  so  much  greater  than  ours,  that  it  would  hide  the  spurs 
of  hills  which  buttress  the  southern  slopes  of  Archimedes,  leav- 
ing only  the  walls  of  the  great  mountain  ring  visible  in  the 
extremest  horizon,  while  between  us  and  them  would  extend 
what  some  still  maintain  to  have  been  the  bed  of  an  ancient 
lunar  ocean,  though  assuredly  no  water  exists  there  now. 

Among  the  many  fanciful  theories  to  account  for  the  forms 
of  the  ringed  plains,  one  (and  this  is  from  a  man  of  science 
whose  ideas  are  always  original)  invokes  the  presence  of  water. 
According  to  it,  these  great  plains  were  once  ocean  beds,  and 
in  them  worked  a  coral  insect,  building  up  lunar  " atolls"  and 
ring-shaped  submarine  mountains,  as  the  coral  polyp  does  here. 
The  highest  summits  of  the  great  rings  thus  formed  were  then 
low  islands,  just  u  a-wash  "  with  the  waves  of  the  ancient  lunar 
sea,  and,  for  aught  we  know,  green  with  feathery  palms.  Then 
came  (in  the  supposition  in  question)  a  time  when  the  ocean 
dried  up,  and  the  mountains  were  left  standing,  as  we  see, 
in  rings,  after  the  cause  of  their  formation  was  gone.  If  it  be 
asked  where  the  water  went  to,  the  answer  is  not  very  obvious 
on  the  old  theories ;  but  those  who  believe  in  them  point  to  the 
extraordinary  cracks  in  the  soil,  like  those  our  engraving  shows, 
as  chasms  and  rents,  by  which  the  vanished  seas,  and  perhaps 
also  the  vanished  air,  have  been  absorbed  into  the  interior. 

If  there  was  indeed  such  an  ancient  ocean,  it  would  have 
washed  the  very  feet  of  the  precipices  on  whose  summits  we 
are  in  imagination  standing,  and  below  us  their  recesses  would 
have  formed  harbors  which  fancy  might  fill  with  commerce, 
and  cities  in  which  we  might  picture  life  and  movement  where 
all  is  now  dead.  It  need  hardly  be  said  that  no  telescope  has 
ever  revealed  their  existence  (if  such  ruins,  indeed,  there  are), 
and  it  may  be  added  that  the  opinion  of  geologists  is,  as  a 
whole,  unfavorable  to  the  presence  of  water  on  the  moon,  even 


#?•-•; 


FIG.   69.  —  THE   LUNAR   APENNINES:    ARCHIMEDES. 


**     in 


THE  PLANETS  AND    THE  MOON.  155 

in  the  past,  from  the;  absence  of  any  clear  evidence  of  erosive 
action ;  but  perhaps  we  are  not  yet  entitled  to  speak  on  these 
points  with  certainty,  and  are  not  forbidden  to  believe  that 
water  may  have  existed  here  in  the  past  by  any  absolute  testi- 
mony to  the  contrary.  The  views  of  those  who  hold  the  larger 
portion  of  the  lunar  craters  to  have  been  volcanic  in  their  forma- 
tion are  far  more  probable ;  and  perhaps  as  simple  an  evidence 
of  the  presumption  in  their  favor  as  we  can  give  is  directly  to 
compare  such  a  lunar  region  as  this,  the  picture  of  which  was 
made  for  us  from  a  model,  with  a  similar  model  made  from 
some  terrestrial  volcanic  region.  Here  (Fig.  70)  is  a  photograph 
of  such  a  modelled  plan  of  the  country  round  the  Bay  of  Naples, 
showing  the  ancient  crater  of  Vesuvius  and  its  central  cone, 
with  other  and  smaller  craters  along  the  sea.  Here,  of  course, 
we  'know  that  the  forms  originated  in  volcanic  action,  and  a  com- 
parison of  them  with  our  moon-drawing  is  most  interesting.  To 
return  to  our  Apennine  region  (Fig.  69),  we  must  admit,  how- 
ever, when  we  consider  the  vast  size  of  these  things  (Archimedes 
is  fifty  miles  in  diameter),  that  they  are  very  different  in  pro- 
portion from  our  terrestrial  craters,  and  that  numbers  of  them 
present  no  central  cone  whatever ;  so  that  if  some  of  them  seem 
clearly  eruptive,  there  are  others  to  which  we  have  great  diffi- 
culties in  making  these  volcanic  theories  apply.  Let  us  look, 
for  instance,  at  still  another  region  (Fig.  71).  It  lies  rather 
above  the  centre  of  the  full  moon,  and  may  be  recognized  also 
on  the  Rutherfurd  photograph ;  and  it  consists  of  the  group  of 
great  ring-plains,  three  of  which  form  prominent  figures  in 
our  cut. 

Ptolemy  (the  lower  of  these  in  the  drawing)  is  an  example  of 
such  a  plain,  whose  diameter  reaches  to  about  one  hundred  and 
fifteen  miles,  so  that  it  encloses  an  area  of  nearly  eight  thousand 
square  miles  (or  about  that  of  the  State  of  Massachusetts),-  within 
which  there  is  no  central  cone  or  point  from  which  eruptive 


156  THE  NEW  ASTRONOMY. 

forces  appear  to  have  acted,  except  the  smaller  craters  it  en- 
closes. On  the  south  we  see  a  pass  in  the  mountain  wall  open- 
ing into  the  neighboring-  ring-plain  of  Alphonsus,  which  is  onlv 
less  in  size ;  and  south  of  this  again  is  Arzachel,  sixty-six  miles 
in  diameter,  surrounded  with  terraced  walls,  rising  in  one  place 
to  a  height  greater  than  that  of  Mont  Blanc,  while  the  central 
cone  is  far  lower.  The  whole  of  the  region  round  about,  though 
not  the  roughest  on  the  moon,  is  rough  and  broken  in  a  way  be- 
yond any  parallel  here,  and  which  may  speak  for  itself;  but 
perhaps  the  most  striking  of  the  many  curious  features  —  at 
least  the  only  one  we  can  pause  to  examine  —  is  what  is  called 
"  The  Railway,"  an  almost  perfectly  straight  line,  on  one  side  of 
which  the  ground  has  abruptly  sunk,  leaving  the  undisturbed 
part  standing  like  a  wall,  and  forming  a  "fault,"  as  geologists 
call  it.  This  is  the  most  conspicuous  example  of  its  kind  in  the 
moon,  but  it  is  only  one  of  many  evidences  that  we  are  looking 
at  a  world  whose  geological  history  has  been  not  wholly  unlike 
our  own.  But  the  moon  contains,  as  has  been  said,  but  the  one- 
eightieth  part  of  the  mass  of  our  globe,  and  has  therefore  cooled 
with  much  greater  rapidity,  so  that  it  has  not  only  gone  through 
the  epochs  of  our  own  past  time,  but  has  in  all  probability  al- 
ready undergone  experiences  which  for  us  lie  far  in  the  future ; 
and  it  is  hardly  less  than  justifiable  language  to  say  that  we  are 
beholding  here  in  some  respects  what  the  face  of  our  world  may 
be  when  ages  have  passed  away. 

To  see  this  more  clearly,  we  may  consider  that  in  general  we 
find  that  the  early  stages  of  cosmical  life  are  characterized  by 
great  heat;  a  remark  of  the  truth  of  which  the  sun  itself  fur- 
nishes the  first  and  most  obvious  illustration.  Then  come 
periods  which  we  appear  to  have  seen  exemplified  in  Jupiter, 
where  the  planet  is  surrounded  by  volumes  of  steam-like  vapor, 
through  which  we  may  almost  believe  we  recognize  the  dull 
glow  of  not  yet  extinguished  fires ;  then  times  like  those  which 


FIG.   70.  —  VESUVIUS   AND  NEIGHBORHOOD   OF   NAPLES. 


THE  PLANETS  AND    THE  MOON.  159 

our  earth  passed  through  before  it  became  the  abode  of  man ; 
and  then  the  times  in  which  human  history  begins.  But  if  this 
process  of  the  gradual  loss  of  heat  go  on  indefinitely,  we  must 
yet  come  to  still  another  era,  when  the  planet  has  grown  too 
cold  to  support  life,  as  it  was  before  too  hot ;  and  this  condition, 
in  the  light  of  some  very  recent  investigations,  it  seems  probable 
we  have  now  before  us  on  the  moon. 

We  have,  it  is  true,  been  taught  until  very  lately  that  the 
side  of  the  moon  turned  sunward  would  grow  hotter  and  hotter 
in  the  long  lunar  day,  till  it  reached  a  temperature  of  two  hun- 
dred to  three  hundred  degrees  Fahrenheit,  and  that  in  the 
equally  long  lunar  night  it  would  fall  as  much  as  this  below 
zero.  But  the  evidence  which  was  supposed  to  support  this 
conclusion  as  to  the  heat  of  the  lunar  day  is  not  supported  by 
recent  experiments  of  the  writer ;  and  if  these  be  trustworthy, 
certain  facts  appear  to  him  to  show  that  the  temperature  of  the 
moon's  surface,  even  under  full  perpetual  sunshine,  must  be 
low,  —  and  this  because  of  the  absence  of  air  there  to  keep  the 
stored  sun-heat  from  being  radiated  away  again  into  space. 

As  we  ascend  the  highest  terrestrial  mountains,  and  get  partly 
above  our  own  protecting  blanket  of  air,  things  do  not  grow 
hotter  and  hotter,  but  colder  and  colder ;  and  it  seems  contrary 
to  the  teachings  of  common  sense  to  believe  that  if  we  could 
ascend  higher  yet,  where  the  air  ceases  altogether,  we  should 
not  find  that  it  grew  colder  still.  But  this  last  condition  (of  air- 
lessness)  is  the  one  which  does  prevail  beyond  a  doubt  in  the 
moon,  on  whose  whole  surface,  then,  there  must  be  (unless  there 
are  sources  of  internal  heat  of  which  we  know  nothing)  condi- 
tions of  temperature  which  are  an  exaggeration  of  those  we  ex- 
perience on  the  summit  of  a  very  lofty  mountain,  where  we 
have  the  curious  result  that  the  skin  may  be  burned  under  the 
solar  rays,  while  we  are  shivering  at  the  same  time  in  what  the 
thermometer  shows  is  an  arctic  cold. 


160  '/'///•;  .YA'ir 

We  have  heard  of  this  often ;  but  a  personal  experience  so 
impressed  the  fact  on  me  that  1  will  relate  it  for  the  benefit  of 

the  reader,  who  mav  wish  to  realize  to  himself  the  actual  condi- 
j 

tions  Avhich  probably  exist  in  the  airless  lunar  mountains  and 
plains  we  are  looking-  at.  He  cannot  go  there;  but  lie  may  go 
if  lie  pleases,  as  I  have  done,  to  the  waterless,  shadeless  waste 
which  stretches  at  the  eastern  slope  of  the  Sierra.  Xevadas  (a 
chain  almost  as  high  and  steep  as  the  lunar  Apennines),  and  live 
some  part  of  July  and  August  in  this  desert,  where  the  ther- 
mometer rises  occasionally  to  one  hundred  and  ten  degrees  in 

o 

the  shade,  and  his  face  is  tanned  till  it  can  tan  no  more,  and  he 
appears  to  himself  to  have  experienced  the  utmost  in  this  way 
that  the  sun  can  do. 

The  sky  is  cloudless,  and  the  air  so  clear  that  all  idea  of  the 
real  distance  and  si/e  of  things  is  lost.  The  mountains,  which 
rise  in  tremendous  precipices  above  him,  seem  like  nmss:co\  ered 
rocks  close  at  hand,  on  the  tops  of  which,  here  and  there,  a  white 
cloth  has  been  dropped;  but  the  "moss"  is  great  primeval 
forests,  and  the  white  cloths  large  isolated  snow-lields,  tanta- 
lizing the  dweller  in  the  burning-  desert  with  their  delusive  near- 
ness. When  I  climbed  the  mountains,  at  an  altitude  of  ten 
thousand  feel  I  already  found  the  coolness  delicious,  but  at  the 
same  time  (by  the  strange  effect  I  have  been  speaking  of)  the 
skin  began  to  burn,  as  though  the  seasoning  in  the  desert 
counted  for  nothing  at  all;  and  as  the  air  grew  thinner  and 
thinner  while  I  mounted  still  higher  and  higher,  though  the 
thermometer  fell,  every  part  of  the  person  exposed  to  the  solar 
rays  presented  the  appearance  of  a  recent  severe  burn  from  an 
actual  fire,  —  and  a  really  severe  burn  it  was,  as  I  can  testifv, — 
and  yet  all  the  while  around  us,  under  this  burning  sun  and 
cloudless  sky,  reigned  a  perpetual  winter  which  made  it  hard 
to  believe  that  torrid  summer  still  lay  below.  The  thinner  the 
air,  then,  the  colder  it  grows,  even  where  we  are  exposed  to  the 


FIG.   71.  —  PTOLEMY  AND  ARZACHEL. 


11 


TIIK  PLAXKTS  AM)    THE  MOON.  103 

sun,  and  the  lower  becomes  the  reading  of  the  thermometer. 
Now,  by  means  of  suitable  apparatus,  it  was  sought  by  the 
writer  to  determine,  while  at  this  elevation  of  fifteen  thousand 
feet,  how  great  the  fall  of  temperature  would  be  if  the  thin  air 
there  could  be  removed  altogether ;  and  the  result  was  that  the 
thermometer  would  under  such  circumstances  fall,  at  any  rate, 
below  zero  in  the  full  sunshine. 

Of  course,  all  this  applies  indirectly  to  the  moon,  above 
whose  surface  (if  these  inferences  be  correct)  the  mercury  in 
the  bulb  of  a  thermometer  would  probably  freeze  and  never 
melt  again  during  the  lunar  day  (and  still  less  during  the  lunar 
night),  —  a  conclusion  which  has  been  reached  through  other 
means  by  Mr.  Ericsson,  —  and  whose  surface  itself  cannot  be  very 
greatly  warmer.  Other  and  direct  measures  of  the  lunar  heat 
are  still  in  progress  while  this  is  being  written,  but  their  prob- 
able result  seems  to  be  already  indicated :  it  is  that  the  moon's 
surface,  even  in  perpetual  sunshine,  must  be  forever  cold.  Just 
how  cold,  is  still  doubtful ;  and  it  is  not  yet  certain  whether  ice, 
if  once  formed  there,  could  ever  melt. 

Here  (Fig.  72)  is  one  more  scene  from  the  almost  unlimited 
field  the  lunar  surface  affords. 

The  most  prominent  things  in  the  landscape  before  us  are 
two  fine  craters  (Mercator  and  Campanus),  each  over  thirty 
miles  in  diameter;  but  we  have  chosen  this  scene  for  remark 
rather  on  account  of  the  great  crack  or  rift  which  is  seen  in  the 
upper  part,  and  which  cuts  through  plain  and  mountain  for  a 
length  of  sixty  miles.  Such  cracks  are  counted  by  hundreds  on 
the  moon,  where  they  are  to  be  seen  almost  everywhere;  and 
other  varieties,  in  fact,  are  visible  on  this  same  plate,  but  we  will 
not  stop  to  describe  them.  This  one  varies  in  width  from  an 
eighth  of  a  mile  to  a  mile ;  and  though  we  cannot  see  to  the 
bottom  of  it,  others  are  known  to  be  at  least  eight  miles  deep, 
and  may  be  indefinitely  deeper. 


104  THE  XEW  ASTROXOM). 

The  edge  of  a  cliff  on  the  earth  commonly  gets  weather-worn 
and  rounded ;  but  here  the  edge  is  sharp,  so  that  a  traveller  along 
the  lunar  plains  would  come  to  the  very  brink  of  this  tremen- 
dous chasm  before  he  had  any  warning  of  its  existence.  It  is 
usually  thus  with  all  such  rifts;  and  the  straightness  and  sharp- 
ness of  the  edge  in  these  cases  suggest  the  appearance  of  an  ice- 
crack  to  the  observer.  I  do  not  mean  to  assert  that  there  is 
more  than  a  superficial  resemblance.  I  do  not  write  as  a  geolo- 
gist ;  but  in  view  of  what  we  have  just  been  reading  of  the  lunar 
cold,  we  may  ask  ourselves  whether,  if  water  ever  did  exist  here, 
we  should  not  expect  to  find  perpetual  ice,  not  necessarily  glit- 
tering, but  covered,  perhaps,  with  the  deposits  of  an  air  laden 
with  the  dust-products  of  later  volcanic  eruptions,  or  even  cov- 
ered in  after  ages,  when  the  air  has  ceased  from  the  moon,  with 
the  slow  deposit  of  meteoric  dust  during  millions  of  years  of 
windless  calm.  What  else  can  we  think  will  become  of  the 
water  on  our  own  earth  if  it  be  destined  to  pass  through  such 
an  experience  as  we  seem  to  see  prophesied  in  the  condition  of 
our  dead  satellite  }. 

The  reader  must  not  understand  me  as  saying  that  there  is 
ice  on  the  moon,  —  only  that  there  is  not  improbably  perpetual 
ice  there  now  if  there  ever  was  water  in  past  time ;  and  he  is  not 
to  suppose  that  to  say  this  is  in  any  way  to  deny  what  set  ins 
the  strong  evidence  of  the  existence  of  volcanic  action  everv- 
where,  for  the  two  things  may  well  have  existed  in  successive 
ages  of  our  satellite's  past,  or  even  have  both  existed  together, 
like  Hecla,  within  our  own  arctic  snows;  and  if  no  sign  of  an\ 
still  active  lunar  volcano  has  been  discovered,  we  appear  to  read 
the  traces  of  their  presence  in  the  past  none  the  less  clearly. 

I  remember  that  at  one  time,  when  living  on  the  lonely  upper 
lava-wastes  of  Mount  Ktna,  which  are  pitted  with  little  craters, 
I  grew  acquainted  with  so  manv  a  chasm  and  rent  filled  with 
these,  that  the  dreary  landscape  appeared  from  above  as  if  a  bit 


.:--< 


» ~  r  >i  >>  %  '; •  -•>.  -  -  *  jr^C-fJi 


FIG.    72.  —  MERCATOR   AND   CAMPANUS. 


THE  PLANETS  AND    THE  MOON.  167 

of  the  surface  of  the  moon  I  looked  up  at  through  the  telescope 
had  been  brought  down  beside  me. 

I  remember,  too,  that  as  I  studied  the  sun  there,  and  watched 
the  volcanic  outbursts  on  its  surface,  I  felt  that  I  possibly  em- 
braced in  a  threefold  picture  as  many  stages  in  the  history  of 
planetary  existence,  through  all  of  which  this  eruptive  action  was 
an  agent,  —  above  in  the  primal  energies  of  the  sun ;  all  around 
me  in  the  great  volcano,  black  and  torn  with  the  fires  that  still 
burn  below,  and  whose  smoke  rose  over  me  in  the  plume  that 
floated  high  up  from  the  central  cone ;  and  finally  in  this  last 
stage  in  the  moon,  which  hung  there  pale  in  the  daylight  sky, 
and  across  whose  face  the  vapors  of  the  great  terrestrial  volcano 
drifted,  but  on  whose  own  surface  the  last  fire  was  extinct. 

We  shall  not  get  an  adequate  idea  of  it  all,  unless  we  add  to 
our  bird's-eye  views  one  showing  a  chain  of  lunar  mountains  as 
they  would  appear  to  us  if  we  saw  them,  as  we  do  our  own  Alps 
or  Apennines,  from  about  their  feet;  and  such  a  view  Fig.  74 
affords  us.  In  the  ban-en  plain  on  the  foreground  are  great 
rifts  such  as  we  have  been  looking  at  from  above,  and  smaller 
craters,  with  their  extinct  cones ;  while  beyond  rise  the  moun- 
tains, ghastly  white  in  the  cold  sunshine,  their  precipices 
crowned  by  no  mountain  fir  or  cedar,  and  softened  by  no 
intervening  air  to  veil  their  nakedness. 

If  the  reader  has  ever  climbed  one  of  the  highest  Alpine 
peaks,  like  those  about  Monte  Rosa  or  the  Matterhorn,  and 
there  waited  for  the  dawn,  he  cannot  but  remember  the  sense 
of  desolation  and  strangeness  due  to  the  utter  absence  of  every- 
thing belonging  to  man  or  his  works  or  his  customary  abode, 
above  all  which  he  is  lifted  into  an  upper  world,  so  novel  and, 
as  it  were,  so  unhuman  in  its  features,  that  he  is  not  likely  to 
have  forgotten  his  first  impression  of  it;  and  this  impression 
gives  the  nearest  but  still  a  feeble  idea  of  what  we  see  with  the 
telescope  in  looking  down  on  such  a  colorless  scene,  where  too 


108  THE   A'A'ir 


no  water  bubbles,  no  tree  can  sigh  in  the  breeze,  no  bird  can 
sing,  —  the  lioine  of  silence. 

But  liere,    above   it,   hangs   a   world  in   the   sky,   which   we 
should  need  to  call  in  color  to  depict,  for  it  is  green  and  yellow 


FIG.  7::.  —  wri  III:I;I:D  HAND. 


with  the  forests  and  the  harvest-fields  that  overspread  its  con- 
tinents, witli  emerald  islands  studding  its  gray  oceans,  over  all 
of  which  sweep  the  clouds  that  bring  the  life-o'ivino-  rain.  It  is 
our  own  world,  which  lights  up  the  dreary  lunar  night,  as  the 
moon  does  ours. 


tr 


THE  PLANETS   AX/)    THE   MOOX.  171 

The  signs  of  age  are  on  the  moon.  It  seems  pitted,  torn,  and 
rent  by  the  past  action  of  long-dead  fires,  till  its  surface  is  like  a 
piece  of  porous  cinder  under  the  magnifying-glass,  —  a  burnt-out 
cinder  of  a  planet,  which  rolls  through  the  void  like  a  ruin  of 
what  has  been ;  and,  more  significant  still,  this  surface  is  wrin- 
kled everywhere,  till  the  analogy  with  an  old  and  shrivelled  face 


FIG.    7").  —  WITHERED   APPLE. 


or  hand  or  fruit  (Figs.  73  and  75),  where  the  puckered  skin  is 
folded  about  a  shrunken  centre,  forces  itself  on  our  attention, 
and  suggests  a  common  cause, — a  something  underlying  the 
analogy,  and  making  it  more  than  a  mere  resemblance. 

The  moon,  then,  is  dead ;  and  if  it  ever  was  the  home  of  a 
race  like  ours,  that  race  is  dead  too.  I  have  said  that  our  New 
Astronomy  modifies  our  view  of  the  moral  universe  as  well  as  of 
the  physical  one ;  nor  do  we  need  a  more  pregnant  instance  than 


\T1  THE   XK\V  ASTRONOMY. 

iii  this  before  us.  In  these  days  of  decay  of  old  creeds  of  the 
eternal,  it  has  been  sought  to  satisfy  man's  yearning-  toward  it 
by  founding  a  new  religion  whose  god  is  Humanity,  and  whose 
hope  lies  in  the  future  existence  of  our  own  race,  in  whose  col- 
lective being  the  individual  who  must  die  may  fancy  his  aims 
and  purpose  perpetuated  in  an  endless  progress.  But,  alas  for 
hopes  looking-  to  this  alone!  we1  are  here  brought  to  face  the 
solemn  thought  that,  like  the  individual,  though  at  a  little  further 
date,  Humanity  itself  may  die! 

In-fore  we  leave  this  dead  world,  let  us  take  a  last  glance  at 
one  of  its  fairest  scenes,  —  that  which  we  obtain  when  looking  at 
a  portion  on  which  the  sun  is  rising,  as  in  this  view  of  Gassendi 
(Fig.  T(J),  in  which  the  dark  part  on  our  right  is  still  the  body  of 
the  moon,  on  which  the  sun  has  not  yet  risen.  Its  nearly  level 
rays  stretch  elsewhere  over  a  surface  that  is,  in  places,  of  a 
strangely  smooth  texture,  contrasting  with  the  ruggedness  of 
the  ordinary  soil,  which  is  here  gathered  into  low  plaits,  that, 
with  the  texture  we  have  spoken  of,  look 

u  Like  maiToxvy  crapes  of  China  silk, 
Or  wrinkled  skin  on  scalded  milk,'' 

as  the}-  lie,  soft  and  almost  beautiful,  in  the  growing  light. 

Where  its  first  beams  are  kindling,  the  summits  cast  their 
shadows  illimitedlv  over  the  darkening  plains  away  on  the  right, 
until  they  melt  away  into  the  night,  —  a  night  which  is  not 
utterly  black,  for  even  here  a  subdued  radiance  comes  from  the 
earth-shine  of  our  own  world  in  the  sky. 

Let  us  leave  here  the  desolation  about  us,  happy  that  we  can 
come  back  at  will  to  that  world,  our  own  familial-  dwelling, 
where  the  meadows  arc  still  green  and  the  birds  still  sing,  and 
where,  better  vet.  still  dwells  our  own  kind,  —  surely  the  world, 
of  ;ill  we  have  found  in  our  wanderings,  which  we  should  our- 
selves have  chosen  to  be  our  home. 


FIG.  76. 


VI. 

METEORS. 

WHAT  is  truth!      What  is  fact,  and  what  is  fancy,  even 
with  regard  to  solid  visible  things  that  we  may  see  and 
handle  ? 

Among  the  many  superstitions  of  the  early  world  and  credu- 
lous fancies  of  the  Middle  Ages,  was  the  belief  that  great  stones 
sometimes  fell  down  out  of  heaven  onto  the  earth. 

Pliny  has  a  story  of  such  a  black  stone,  big  enough  to  load 
a  chariot ;  the  Mussulman  still  adores  one  at  Mecca ;  and  a  me- 
diaeval emperor  of  Germany  had  a  sword  which  was  said  to 
have  been  forged  from  one  of  these  bolts  shot  out  of  the  blue. 
But  with  the  revival  of  learning,  people  came  to  know  better ! 
That  stones  should  fall  down  from  the  sky  was  clearly,  they 
thought,  an  absurdity ;  indeed,  according  to  the  learned  opinion 
of  that  time,  one  would  hardly  ask  a  better  instance  of  the  dif- 
ference between  the  realities  which  science  recognized  and  the 
absurdities  which  it  condemned  than  the  fancy  that  such  a  thing 
could  be.  So  at  least  the  matter  looked  to  the  philosophers  of 
the  last  century,  who  treated  it  much  as  they  might  treat  certain 
alleged  mental  phenomena,  for  instance,  if  they  were  alive  to- 
day, and  at  first  refused  to  take  any  notice  of  these  stories,  when 
from  time  to  time  they  still  came  to  hand.  When  induced  to 
give  the  matter  consideration,  they  observed  that  all  the  condi- 
tions for  scientific  observation  were  violated  by  these  bodies, 
since  the  wonder  always  happened  at  some  far-off  place  or  at 


17(3  THE  NEW  ASTRONOMY. 

some  past  time,  and  (suspicious  circumstance  !)  the  stones  onl y 
fell  in  the  presence  of  ignorant  and  unscientific  witnesses,  and 
never  when  scientific  men  were  at  hand  to  examine  the  facts. 
That  there  were  many  worthy,  if  ignorant,  men  who  asserted 
that  they  had  seen  such  stones  fall,  seen  them  with  their  very 
eyes,  and  held  them  in  their  own  hands,  was  accounted  for  by 
the  general  love  of  the  marvellous  and  by  the  ignorance  of  the 
common  mind,  unlearned  in  the  conditions  of  scientific  obser- 
vation, and  unguided  by  the  great  principle  of  the  uniformity  of 
the  Laws  of  Nature. 

Such  a  tone,  of  course,  cannot  be  heard  among  us,  who  never 
hastily  pronounce  anything  a  departure  from  the  "  Laws  of 
Nature,"  while  uncertain  that  these  can  be  separated  from  the 
laws  of  the  fallible  human  mind,  in  which  alone  Nature  is  seen. 
But  in  the  last  century  philosophers  had  not  yet  become  humble, 
or  scientific  men  diffident  of  the  absoluteness  of  their  own  knowl- 
edge, and  so  it  seemed  that  no  amount  of  evidence  Avas  enough 
to  gain  an  impartial  hearing  in  the  face  of  the  settled  belief  that 
the  atmosphere  extended  only  a  few  miles  above  the  earth's  sur- 
face, and  that  the  region  beyond,  whence  alone  such  things 
on ild  come,  was  an  absolute  void  extending  to  the  nearest 
planet. 

It  used  to  be  supposed  that  we  were  absolutely  isolated,  not 
only  from  the  stars  but  from  other  planets,  by  vast  empty  spaces 
extending  from  world  to  world,  —  regions  altogether  vacant  ex- 
cept for  some  vagrant  comet;  but  of  late  years  we  are  growing 
to  have  new  ideas  on  this  subject,  and  not  only  to  consider  space 
as  far  from  void  or  tenantless,  but  to  admit,  as  a  possibility  at 
least,  that  there  is  a  sort  of  continuity  between  our  very  earth's 
surface,  the  air  above  it,  and  all  which  lies  beyond  the  blue 
overarching  dome  of  our  own  sky.  Our  knowledge  of  the 
physical  nature  of  the  universe  without  has  chiefly  come  from 
what  the  spectroscope,  overleaping  the  space  between  us  and 


FIG.   77. —  THE  CAMP  AT   MOUNT   WHITNEY. 
(PROM   "  PROFESSIONAL  PAPERS  OF  THE   SIGNAL  SERVICE,"   VOL.    XV.) 


MKTEORS.  179 

the  stars,  has  taught  us  of  them ;  as  a  telegram  might  report  to 
us  the  existence  of  a  race  across  the  ocean,  without  telling  any- 
thing of  what  lay  between.  It  would  be  a  novel  path  to  the 
stars,  and  to  the  intermediate  regions  whence  these  once  mythi- 
cal stones  are  now  actually  believed  to  come,  if  we  could  take 
the  reader  to  them  by  a  route  which  enabled  us  to  note  each 
step  of  a  continuous  journey  from  the  earth's  surface  out  into 
the  unknown ;  but  if  we  undertake  to  start  upon  it,  he  will  un- 
derstand that  we  must  almost  at  the  outset  leave  the  ground  of 
comparative  certainty  on  which  we  have  hitherto  rested,  and 
need  to  speak  of  things  on  this  road  which  are  still  but  proba- 
bilities, and  even  some  which  are  little  more  than  conjectures, 
before  we  get  to  the  region  of  comparative  certainty  again,  —  a 
region  which,  strange  to  say,  exists  far  away  from  us,  while  that 
of  doubt  lies  close  at  hand,  for  we  may  be  said  without  exag- 
geration to  know  more  about  Sirius  than  about  the  atmosphere 
a  thousand  miles  above  the  earth's  surface ;  indeed,  it  would  be 
more  just  to  say  that  we  are  sure  not  only  of  the  existence  but 
of  the  elements  that  compose  a  star,  though  a  million  of  times 
as  far  off  as  the  sun,  while  at  the  near  point  named  we  are  not 
sure  of  so  much  as  that  the  atmosphere  exists  at  all. 

To  begin  our  outward  journey  in  a  literal  sense,  we  might 
rise  from  the  earth's  surface  some  miles  in  a  balloon;  when  we 
should  find  our  progress  stayed  by  the  rarity  of  the  air.  Below 
us  would  be  a  gray  cloud-ocean,  through  which  we  could  see 
here  and  there  the  green  earth  beneath,  while  above  us  there 
would  still  be  something  in  the  apparently  empty  air,  for  if 
the  sun  has  just  set  it  will  still  be  light  all  round  us.  Something 
then,  in  a  cloudless  sky,  still  exists  to  reflect  the  rays  towards 
us,  and  this  something  is  made  up  of  separately  invisible  specks 
of  dust  and  vapor,  but  very  largely  of  actual  dust,  which  prob- 
ably forms  the  nucleus  of  each  mist-particle.  That  discrete 
matter  of  some  kind  exists  here  has  long  been  recognized  from 


180  THE  NEW  ASTRONOMY. 

the  phenomena  of  twilight ;  but  it  is,  I  think,  only  recently  that 
we  are  coming  to  admit  that  a  shell  of  actual  solid  particles  in 
the  form  of  dust  probably  encloses  the  whole  globe,  up  to  far 
above  the  highest  clouds. 

In  1881  the  writer  had  occasion  to  conduct  a  scientific  expe- 
dition to  the  highest  point  in  the  territories  of  the  United  States, 
on  one  of  the  summits  of  the  Sierra  Nevadas  of  Southern  Cali- 
fornia, which  rise  even  above  the  Rocky  Mountains. 

The  illustration  on  page  177  represents  the  camp  occupied  by 
this  party  below  the  summit,  where  the  tents,  which  look  as  if  in 
the  bottom  of  a  valley,  are  yet  really  above  the  highest  zone  of 
vegetation,  and  at  an  altitude  of  nearly  twelve  thousand  feet. 

Still  above  these  rise  the  precipices  of  barren  rock  seen  in  the 
background,  their  very  bases  far  above  the  highest  visible  dust- 
clouds,  which  overspread  like  a  sea  the  deserts  at  the  mountain's 
foot,  —  precipices  which  when  scaled  lift  the  observer  into  what 
is,  perhaps,  the  clearest  and  purest  air  to  be  found  in  the  world. 
It  will  be  seen  from  the  mere  looks  of  the  landscape  that  we  are 
far  away  here  from  ordinary  sources  of  contamination  in  the 
atmosphere.  Yet  even  above  here  on  the  highest  peak,  where 
we  felt  as  if  standing  on  the  roof  of  the  continent  and  elevated 
into  the  great  aerial  currents  of  the  globe,  the  telescope  showed 
particles  of  dust  in  the  air,  which  the  geologists  deemed  to  have 
probably  formed  part  of  the  soil  of  China  and  to  have  been 
borne  across  the  Pacific,  but  which  also,  as  we  shall  see  later, 
may  owe  something  to  the  mysterious  source  of  the  phenomena 
already  alluded  to. 

It  is  far  from  being  indifferent  to  us  that  the  dust  is  there; 
for,  to  mention  nothing  else,  without  it,  it  would  be  night  till 
the  sunrise,  and  black  night  again  as  soon  as  the  sun's  edge 
disappeared  below  the  horizon.  The  morning  and  the  evening 
twilight,  which  in  northern  latitudes  increase  our  average  time 
of  light  by  some  hours,  and  add  very  materially  to  the  actual 


METKOHS.  181 

days  of  man's  life,  are  probably  due  almost  wholly  to  particles 
scarcely  visible  in  the  microscope,  and  to  the  presence  of  such 
atoms,  smaller  than  the  very  motes  ordinarily  seen  in  the  sun- 
beam, which,  as  Mr.  Aitken  has  shown,  fill  the  air  we  breathe,  - 
so  minute  and  remote  are  the  causes  on  which  the  habits  of  life 
depend. 

Before  we  can  see  that  a  part  of  this  impalpable,  invisible 
dust  is  also  perhaps  a  link  between  our  world  and  other  mem- 
bers of  the  solar  system,  we  must  ask  how  it  gets  into  the  atmos- 
phere. Is  it  blown  up  from  the  earth,  or  does  it  fall  down  out 
of  the  miscalled  "void"  of  space! 

If  we  cast  a  handful  of  dust  into  the  air,  it  will  not  mount 
far  above  the  hand  unless  we  set  the  air  in  motion  with  it,  as  in 
ascending  smoke-currents ;  and  the  greatest  explosions  we  can 
artificially  produce,  hurl  their  finer  products  but  a  few  hundred 
feet  at  most  from  the  soil.  Utterly  different  are  the  forces  of 
Nature.  We  have  on  page  183  a  reproduction  from  a  photo- 
graph of  an  eruption  of  Vesuvius,  —  a  mere  toy-volcano  com- 
pared to  Etna  or  Hecla.  But  observe  the  smoke-cloud  which 
rises  high  in  the  sunshine,  looking  solid  as  the  rounded  snows 
of  an  Alp,  while  the  cities  and  the  sea  below  are  in  the  shadow. 
The  smoke  that  mounts  from  the  foreground,  where  the  burning 
lava-streams  are  pouring  over  the  surface  and  firing  the  woods, 
is  of  another  kind  from  that  rolling  high  above.  This  comes 
from  within  the  mountain,  and  is  composed  of  clouds  of  steam 
mingled  with  myriads  of  dust-particles  from  the  comminuted 
products  of  the  earth's  interior ;  and  we  can  see  ourselves  that  it 
is  borne  away  on  a  level,  miles  high  in  the  upper  air. 

But  what  is  this  to  the  eruption  of  Sumbawa  or  Krakatao  ? 
The  latter  occurred  in  1883,  and  it  will  be  remembered  that  the 
air-wave  started  by  the  explosion  was  felt  around  the  globe,  and 
that,  probably  owing  to  the  dust  and  water-vapor  blown  into  the 
atmosphere,  the  sunsets  even  in  America  became  of  that  extra- 


182  THE  NEW  ASTRONOMY. 

ordinary  crimson  we  all  remember  three  years  ago ;  and  coin- 
cidently,  that  dim  reddish  halo  made  its  appearance  about  the 
sun,  the  world  over,  which  is  hardly  yet  gone.1  Very  careful 
estimates  of  the  amount  of  ashes  ejected  have  been  made ;  and 
though  most  of  the  heavier  particles  are  known  to  have  fallen 
into  the  sea  within  a  few  miles,  a  certain  portion  —  the  lightest 
—  was  probably  earned  by  the  explosion  far  above  the  lower 
strata  of  the  atmosphere,  to  descend  so  slowly  that  some  of  it 
may  still  be  there.  Of  this  lighter  class  the  most  careful  esti- 
mates must  be  vague ;  but  according  to  the  report  of  the  official 
investigation  by  the  Dutch  Government,  that  which  remained 
floating  is  something  enormous.  An  idea  of  its  amount  may 
be  gained  by  supposing  these  impalpable  and  invisible  particles 
to  condense  again  from  the  upper  sky,  and  to  pour  down  on 
the  highest  edifice  in  the  world,  the  Washington  Monument.  If 
the  dust  were  allowed  to  spread  out  on  all  sides,  till  the  pyra- 
midal slope  was  so  flat  as  to  be  permanent,  the  capstone  of  the 
monument  would  not  only  be  buried  before  the  supply  was 
exhausted,  but  buried  as  far  below  the  surface  as  that  pinnacle 
is  now  above  it. 

Of  the  explosive  suddenness  with  which  the  mass  was  hurled, 
we  can  judge  something  (comparing  small  things  with  great)  by 
the  explosion  of  dynamite. 

It  happened  once  that  the  writer  was  standing  by  a  car  in 
which  some  railway  porters  were  lifting  boxes.  At  that  moment 
came  an  almost  indescribable  sound,  for  it  was  literally  stun- 
ning, though  close  and  sharp  as  the  crack  of  a  whip  in  one's 
hand,  and  yet  louder  than  the  nearest  thunder-clap.  The  men 
leaped  from  the  car,  thinking  that  one  of  the  boxes  had  exploded 
between  them;  but  the  boxes  were  intact,  and  we  saw  what 
seemed  a  pillar  of  dust  rising  above  the  roof  of  the  station,  hun- 
dreds of  yards  away.  When  we  hurried  through  the  building, 

1  In  January,  1887. 


FIG.   78.  —  VESUVIUS  DURING  AN  ERUPTION. 


METEORS.  185 

we  found  nothing  on  the  other  side  but  a  bare  plain,  extending 
over  a  mile,  and  beyond  this  the  actual  scene  of  the  explosion 
that  had  seemed  to  be  at  our  feet.  There  had  been  there,  a  few 
minutes  before,  extensive  buildings  and  shops  belonging  to  the 
railroad,  and  sidings  on  which  cars  were  standing,  two  of  which, 
loaded  with  dynamite,  had  exploded. 

Where  they  had  been  was  a  crater-like  depression  in  the 
earth,  some  rods  in  diameter ;  the  nearest  buildings,  great  solid 
structures  of  brick  and  stone,  had  vanished,  and  the  more  distant 
wooden  ones  and  the  remoter  lines  of  freight-cars  on  the  side- 
tracks presented  a  curious  sight,  for  they  were  not  shattered 
so  much  as  bent  and  leaning  every  way,  as  though  they  had 
been  built  of  pasteboard,  like  card-houses,  and  had  half 
yielded  to  some  gigantic  puff  of  breath.  All  that  the  explo- 
sion had  shot  skyward  had  settled  to  earth  or  blown  away 
before  we  got  in  sight  of  the  scene,  which  was  just  as  quiet 
as  it  had  been  a  minute  before.  It  was  like  one  of  the  changes 
of  a  dream. 

Now,  it  is  of  some  concern  to  us  to  know  that  the  earth  holds 
within  itself  similar  forces,  on  an  incomparably  greater  scale. 
For  instance,  the  explosion  which  occurred  at  Krakatao,  at  five 
minutes  past  ten,  on  the  27th  of  August,  1883,  according  to  offi- 
cial evidence,  was  heard  at  a  distance  of  eighteen  hundred  miles, 
and  the  puff  of  its  air-wave  injured  dwellings  two  hundred  miles 
distant,  and,  we  repeat,  carried  into  the  highest  regions  of  the 
atmosphere  and  around  the  world  matter  which  it  is  at  least 
possible  still  affects  the  aspect  of  the  sun  to-day  from  New  York 
or  Chicago. 

Do  not  the  great  flames  which  we  have  seen  shot  out  from 
the  sun  at  the  rate  of  hundreds  of  miles  a  second,  the  immense 
and  sudden  perturbations  in  the  atmosphere  of  Jupiter,  and  the 
scarred  surface  of  the  moon,  seem  to  be  evidences  of  analogous 
phenomena,  common  to  the  whole  solar  system,  not  wholly 


186  THE  NEW  ASTRONOMY. 

unconnected  with  those  of  earthquakes,  and  which  we  can  still 
study  in  the  active  volcanoes  of  the  earth? 

If  the  explosion  of  gunpowder  can  hurl  a  cannon-shot  three 
or  four  miles  into  the  air,  how  far  might  the  explosion  of  Kra- 
katao  cast  its  fragments?  At  first  we  might  think  there  must 
be  some  proportionality  between  the  volume  of  the  explosion 
and  the  distance,  but  this  is  not  necessarily  so.  Apart  from  the 
resistance  of  the  air,  it  is  a  question  of  the  velocity  with  which 
the  thing  is  shot  upward,  rather  than  the  size  of  the  gun,  or  the 
size  of  the  thing  itself,  and  with  a  sufficient  velocity  the  pro- 
jectile would  never  fall  back  again.  "  What  goes  up  must  come 
down,"  is,  like  most  popular  maxims,  true  only  within  the  limits 
of  ordinary  experience ;  and  even  were  there  nothing  else  in  the 
universe  to  attract  it,  and  though  the  earth's  attraction  extend  to 
infinity,  so  that  the  body  would  never  escape  from  it,  it  is  yet 
quite  certain  that  it  would,  with  a  certain  initial  velocity  (very 
moderate  in  comparison  with  that  of  the  planet  itself),  go  up 
and  never  come  back ;  while  under  other  and  possible  conditions 
it  might  voyage  out  into  space  on  a  comet-like  orbit,  and  be 
brought  back  to  the  earth,  perhaps  in  after  ages,  when  the  origi- 
nal explosion  had  passed  out  of  memory  or  tradition.  But  be- 
cause all  this  is  possible,  it  does  not  follow  that  it  is  necessarily 
true ;  and  if  the  reader  ask  why  he  should  then  be  invited  to 
consider  such  suppositions  at  all,  we  repeat  that  in  our  journey 
outward,  before  we  come  to  the  stars,  of  which  we  know  some- 
thing, we  pass  through  a  region  of  which  we  know  almost 
nothing;  and  this  region,  which  is  peopled  by  the  subjects  of 
conjecture,  is  the  scene,  if  not  the  source,  of  the  marvel  of  the 
falling  stones,  concerning  which  the  last  century  was  so  incredu- 
lous, but  for  which  we  can,  aided  by  what  has  just  been  said, 
now  see  at  least  a  possible  cause,  and  to  which  we  now  return. 

Stories  of  falling  stones,  then,  kept  arising  from  time  to  time 
during  the  last  century  as  they  had  always  done,  and  philoso- 


MKTKORS.  187 

pliers  kept  on  disbelieving  them  as  they  had  always  done,  till 
an  event  occurred  which  suddenly  changed  scientific  opinion  to 
compulsory  belief. 

On  the  26th  of  April,  1803,  there  fell,  not  in  some  far-off  part 
of  the  world,  but  in  France,  not  one  alone,  but  many  thousand 
stones,  over  an  area  of  some  miles,  accompanied  with  noises  like 
the  discharge  of  artillery.  A  committee  of  scientific  men  visited 
the  spot  on  the  part  of  the  French  Institute,  and  brought  back 
not  only  the  testimony  of  scores  of  witnesses  or  auditors,  but  the 
stones  themselves.  Soon  after  stones  fell  in  Connecticut,  and 
here  and  elsewhere,  as  soon  as  men  were  prepared  to  believe, 
they  found  evidence  multiplied ;  and  such  falls,  it  is  now  ad- 
mitted, though  rare  in  any  single  district,  are  of  what  may  be 
called  frequent  occurrence  as  regards  the  world  at  large,  —  for, 
taking  land  and  sea  together,  the  annual  stone-falls  are  probably 
to  be  counted  by  hundreds. 

It  was  early  noticed  that  these  stones  consisted  either  of  a 
peculiar  alloy  of  iron,  or  of  minerals  of  volcanic  origin,  or  both ; 
and  the  first  hypothesis  was  that  they  had  just  been  shot  out 
from  terrestrial  volcanoes.  As  they  were  however  found,  as  in 
the  case  of  the  Connecticut  meteorite,  thousands  of  miles  from 
any  active  volcanoes,  and  were  seen  to  fall,  not  vertically  down, 
but  as  if  shot  horizontally  overhead,  this  view  was  abandoned. 
Next  the  idea  was  suggested  that  they  were  coming  from  vol- 
canoes in  the  moon ;  and  though  this  had  little  to  recommend  it, 
it  was  adopted  in  default  of  a  better,  and  entertained  down  to  a 
comparatively  very  recent  period.  These  stones  are  now  col- 
lected in  museums,  where  any  one  may  see  them,  and  are  to 
be  had  of  the  dealers  in  such  articles  by  any  who  wish  to  buy 
them.  They  are  coming  to  have  such  a  considerable  money 
value  that,  in  one  case  at  least,  a  lawsuit  has  been  instituted  for 
their  possession  between  the  finder,  who  had  picked  the  stones 
up  on  ground  leased  to  him,  and  claimed  them  under  the  tenant's 


188  THE  NEW  ASTRONOMY. 

right  to  wild  game,  and  his  landlord,  who  thought  they  were 
his  as  part  of  the  real  estate. 

Leaving  the  decision  of  this  novel  law-point  to  the  lawyers, 
let  us  notice  some  facts  now  well  established. 

The  fall  is  usually  preceded  by  a  thundering  sound,  some- 
times followed  or  accompanied  by  a  peculiar  noise  described  MS 
like  that  of  a  flock  of  ducks  rising  from  the  water.  The  prin- 
cipal sound  is  often,  however,  far  louder  than  any  thunder,  and 
sometimes  of  stunning  violence.  At  night  this  is  accompanied 
by  a  blaze  of  lightning-like  suddenness  and  whiteness, 'and  the 
stones  commonly  do  not  fall  vertically,  but  as  if  shot  from  a 
cannon  at  long  range.  They  are  usually  burning  hot,  but  in 
at  least  one  authenticated  instance  one  was  so  intensely  cold 
that  it  could  not  be  handled.  They  are  of  all  sizes,  from  tons 
to  ounces,  comparatively  few,  however,  exceeding  a  hundred- 
weight, and  they  are  oftenest  of  a  rounded  form,  or  looking  like 
pieces  of  what  was  originally  round,  and  usually  wholly  or 
partly  covered  with  a  glaze  formed  of  the  fused  substance  itself. 
If  we  slowly  heat  a  lump  of  loaf  sugar  all  through,  it  will  form 
a  pastv  mass,  while  Ave  may  also  hold  it  without  inconvenience 
in  our  fingers  to  the  gas-flame  a  few  seconds,  when  it  will  be 
melted  only  on  the  side  next  the  sudden  heat,  and  rounded  by 
the  melting.  The  sharp  contrast  of  the  melted  and  the  rough 
side  is  something  like  that  of  the  meteorites;  and  just  as  the 
sugar  does  not  burn  the  hand,  though  close  to  where  it  is 
brought  suddenly  to  a  melting  heat,  a  mass  of  ironstone  may 
be  suddenly  heated  on  the  surface,  while  it  remains  cold  on  the 
inside.  But,  however  it  got  there,  the  stone  undoubtedly  comes 
from  the  intensely  cold  spaces  above  the  upper  air ;  and  what  is 
the  source  of  such  a  heat  that  it  is  melted  in  the  cold  air,  and  in 
a  few  seconds  .' 

Everybody  has  noticed  that  if  we  move  a  fan  gently,  the  air 
parts  before  it  with  little  effort,  while,  when  we  try  to  fan  vio- 


FIG.   79.  —  METEORS   OBSERVED   NOV.    13  AND   14,  1868,   BETWEEN   MIDNIGHT 
AND  FIVE   O'CLOCK,   A.  M. 


&••       ;« 


METEORS.  191 

lently,  the  same  air  is  felt  to  react ;  yet  if  we  go  on  to  say  that 
if  the  motion  is  still  more  violent  the  atmosphere  will  resist  like 
a  solid,  against  which  the  fan,  if  made  of  iron,  would  break  in 
pieces,  this  may  seem  to  some  an  unexpected  property  of  the 
"  nimble"  air  through  which  we  move  daily.  Yet  this  is  the 
case ;  and  if  the  motion  is  only  so  quick  that  the  air  cannot  get 
out  of  the  way,  a  body  hurled  against  it  will  rise  in  temperature 
like  a  shot  striking  an  armor-plate.  It  is  all  a  question  of  speed, 
and  that,  of  the  meteorite  is  known  to  be  immense.  One  has 
been  seen  to  fly  over  this  country  from  the  Mississippi  to  the 
Atlantic  in  an  inappreciably  short  time,  probably  in  less  than 
two  minutes ;  and  though  at  a  presumable  height  of  over  fifty 
miles,  the  velocity  with  which  it  shot  by  gave  every  one  the  im- 
pression that  it  went  just  above  his  head,  and  some  witnesses  of 
the  unexpected  apparition  looked  the  next  day  to  see  if  it  had 
struck  their  chimneys.  The  heat  developed  by  arrested  motion 
in  the  case  of  a  mass  of  iron  moving  twenty  miles  a  second  can 
be  calculated,  and  is  found  to  be  much  more  than  enough,  not 
only  to  melt  it,  but  to  turn  it  into  vapor ;  though  what  probably 
does  happen  is,  according  to  Professor  Newton,  that  the  melted 
surface-portions  are  wiped  away  by  the  pressure  of  the  air  and 
volatilized  to  form  the  luminous  train,  the  interior  remaining 
cold,  until  the  difference  of  temperature  causes  a  fracture,  when 
the  stone  breaks  and  pieces  fall,  —  some  of  them  at  red-hot  heat, 
some  of  them  possibly  at  the  temperature  of  outer  space,  or  far 
below  that  of  freezing  mercury. 

Where  do  these  stones  come  from  I  What  made  them  ?  The 
answer  is  not  yet  complete ;  but  if  a  part  of  the  riddle  is  already 
yielding  to  patience,  it  is  worthy  of  note,  as  an  instance  of  the 
connection  of  the  sciences,  that  the  first  help  to  the  solution 
of  this  astronomical  enigma  came  from  the  chemists  and  the 
geologists. 

The  earliest  step  in  the  study,  which  has  now  been  going  on 


192  THE  NEW  ASTRONOMY. 

for  many  years,  was  to  analyze  the  meteorite,  and  the  first  result 
was  that  it  contained  no  elements  not  found  on  this  planet.  The 
next  was  that,  though  none  of  these  elements  were  unknown, 
they  were  not  combined  as  we  see  them  in  the  minerals  we  dig 
from  the  earth.  Next  it  was  found  that  the  combinations,  if  un- 
familiar at  the  earth's  surface  and  nowhere  reproduced  exactly, 
wrere  at  least  very  like  such  as  existed  down  beneath  it,  in  lower 
strata,  as  far  as  we  can  judge  by  specimens  of  the  earth's  interior 
cast  up  from  volcanoes.  Later,  a  resemblance  was  recognized 
in  the  elements  of  the  meteorites  to  those  found  by  the  spectro- 
scope in  shooting  stars,  though  the  spectroscopic  observation  of 
the  latter  is  too  difficult  to  have  even  yet  proceeded  very  far. 
And  now,  within  the  last  few  years,  we  seem  to  be  corning  near 
to  a  surprising  solution. 

It  has  now  been  shown  that  meteoric  stories  sometimes  con- 
tain pieces  of  essentially  different  rocks  fused  together,  and 
pieces  of  detritus,  —  the  wearing  down  of  older  rocks.  Thus,  as 
we  know  that  sandstone  is  made  of  compacted  sand,  and  sand 
itself  was  in  some  still  earlier  time  part  of  rocks  worn  down  by 
friction,  —  when  it  is  shown,  as  it  has  been  by  M.  Meunier,  that 
a  sandstone  penetrated  by  metallic  threads  (like  some  of  our  ter- 
restrial formations)  has  come  to  us  in  a  meteorite,  the  conclu- 
sion that  these  stones  may  be  part  of  some  old  world  is  one  that, 
however  startling,  we  cannot  refuse  at  least  to  consider.  Ac- 
cording to  this  view,  there  may  have  been  a  considerable  planet 
near  the  earth,  which,  having  reached  the  last  stage  of  planetary 
existence  shown  in  the  case  of  our  present  moon,  went  one  step 
further,  —  went,  that  is,  out  of  existence  altogether,  by  literal 
breaking  up  and  final  disappearance.  We  have  seen  the  actual 
moon  scarred  and  torn  in  every  direction,  and  are  asked  to 
admit  the  possibility  that  a  continuance  of  the  process  on  a 
similar  body  has  broken  it  up  into  the  fragments  that  come  to 
us.  We  do  not  say  that  this  is  the  case,  but  that  (as  regards 


METEORS.  193 

the  origin  of  some  of  the  meteorites  at  least)  we  cannot  at 
present  disprove  it.  We  may,  at  any  rate,  present  to  the  novelist 
seeking  a  new  motif  that  of  a  meteorite  bringing  to  us  the  story 
of  a  lost  race,  in  some  fragment  of  art  or  architecture  of  its  lost 
world ! 

We  are  not  driven  to  this  world- shattering  hypothesis  by  the 
absence  of  others,  for  we  may  admit  these  to  be  fragments  of  a 
larger  body  without  necessarily  concluding  that  it  was  a  world 
like  ours,  or,  even  if  it  were,  that  the  world  which  sent  them  to 
us  is  destroyed.  In  view  of  what  we  have  been  learning  of  the 
tremendous  explosive  forces  we  see  in  action  on  the  sun  and 
probably  on  other  planets,  and  even  in  terrestrial  volcanoes  to- 
day, it  is  certainly  conceivable  that  some  of  these  stones  may 
have  been  ejected  by  some  such  process  from  any  sun,  or  star, 
or  world  we  see.  The  reader  is  already  prepared  for  the  sug- 
gestion that  part  of  them  may  be  the  product  of  terrestrial 
volcanoes  in  early  epochs,  when  our  planet  was  yet  glowing 
sunlike  with  its  proper  heat,  and  the  forces  of  Nature  were 
more  active ;  and  that  these  errant  children  of  mother  earth's 
youth,  after  circulating  in  lengthened  orbits,  are  coming  back  to 
her  in  her  age. 

Do  not  let  us,  however,  forget  that  these  are  mostly  specu- 
lations only,  and  perhaps  the  part  of  wisdom  is  not  to  speculate 
at  all  till  we  learn  more  facts ;  but  are  not  the  facts  themselves 
as  extraordinary  as  any  invention  of  fancy  ? 

Although  it  is  true  that  the  existence  of  the  connection  be- 
tween shooting  stars  and  meteorites  lacks  some  links  in  the 
chain  of  proof,  we  may  very  safely  consider  them  together; 
and  if  we  wish  to  know  what  the  New  Astronomy  has  done  for 
us  in  this  field,  we  should  take  up  some  treatise  on  astronomy 
of  the  last  century.  We  turn  in  one  to  the  subject  of  falling 
stars,  and  find  that  "this  species  of  Star  is  only  a  light  Exhala- 
tion, almost  wholly  sulphurous,  which  is  inflamed  in  the  free  Air 

13 


194  THE  NEW  ASTRONOMY. 

much  after  the  same  manner  as  Thunder  in  a  Cloud  by  the 
blowing  of  the  Winds."  That  the  present  opinion  is  different, 
we  shall  shortly  notice. 

All  of  us  have  seen  shooting  stars,  and  they  are  indeed  some- 
thing probably  as  old  as  this  world,  and  have  left  their  record 
in  mythology  as  well  as  in  history.  According  to  Moslem  tra- 
dition, the  evil  genii  are  accustomed  to  fly  at  night  up  to  the 
confines  of  heaven  in  order  to  overhear  the  conversation  of 
the  angels,  and  the  shooting  stars  are  the  fiery  arrows  hurled 
by  the  latter  at  their  lurking  foes,  with  so  good  an  aim  that 
we  are  told  that  for  every  falling  star  we  may  be  sure  that 
there  is  one  spirit  of  evil  the  less  in  the  world.  The  scientific 
view  of  them,  however,  if  not  so  consolatory,  is  perhaps  more 
instructive,  and  we  shall  here  give  most  attention  to  the 
latter. 

To  begin  with,  there  have  been  observed  in  history  certain 
times  when  shooting  stars  were  unusually  numerous.  The  night 
when  King  Ibrahim  Ben  Ahmed  died,  in  October,  902,  was 
noted  by  the  Arabians  as  remarkable  in  this  way ;  and  it  has 
frequently  been  observed  since,  that,  though  we  can  always  see 
some  of  these  meteors  nightly,  there  are  at  intervals  very  special 
displays  of  them.  The  most  notable  modern  one  was  on  Nov. 
13,  1833,  and  this  was  visible  over  much  of  the  North  American 
continent,  forming  a  spectacle  of  terrifying  grandeur.  An  eye- 
witness in  South  Carolina  wrote:  — 

"  I  was  suddenly  awakened  by  the  most  distressing  cries  that  ever 
fell  on  my  ears.  Shrieks  of  horror  and  cries  for  mercy  I  could  hear 
from  most  of  the  negroes  of  the  three  plantations,  amounting  in  all  to 
about  six  hundred  or  eight  hundred.  While  earnestly  listening  for  the 
cause  I  heard  a  faint  voice  near  the  door,  calling  my  name.  I  arose, 
and,  taking  my  sword,  stood  at  the  door.  At  this  moment  I  heard  the 
same  voice  still  beseeching  me  to  rise,  and  saying,  <  0  my  God,  the  world 
is  on  fire ! '  T  then  opened  the  door,  and  it  is  difficult  to  say  which 
excited  me  the  most  —  the  awfulness  of  the  scene,  or  the  distressed  cries 


METEORS.  195 

of  the  negroes.     Upwards  of  one  hundred  lay  prostrate  on  the  ground,— 
some  speechless  and  some  with  the  bitterest  cries,  but  with  their  hands 
raised,  imploring  God  to  save  the  world  and  them.     The  scene  was  truly 
u w ful ;  for  never  did  rain  fall  much  thicker  than  the  meteors  fell  toward 
the  earth  ;  east,  west,  north,  and  south,  it  was  the  same." 

The  illustration  on  page  189  does  not  exaggerate  the  number 
of  the  fiery  flashes  at  such  a  time,  though  the  zigzag  course 
which  is  observed  in  some  is  hardly  so  common  as  it  here 
appears. 

When  it  was  noted  that  the  same  date,  November  13th,  had 
been  distinguished  by  star-showers  in  1831  and  1832,  and  that 
the  great  shower  observed  by  Humboldt  in  1799  was  on  this 
day,  the  phenomenon  wras  traced  back  and  found  to  present 
itself  about  every  thirty-three  years,  the  tendency  being  to  a 
little  delay  on  each  return ;  so  that  Professor  Newton  and  others 
have  found  it  possible  with  this  clew  to  discover  in  early  Arabic 
and  other  mediaeval  chronicles,  and  in  later  writers,  descriptions 
which,  fitted  together,  make  a  tolerably  continuous  record  of  this 
thirty-three-year  shower,  beginning  with  that  of  King  Ibrahim 
already  alluded  to.  The  shower  appeared  again  in  November, 
1867  and  1868,  with  less  display,  but  with  sufficient  brilliance 
to  make  the  writer  well  remember  the  watch  through  the  night, 
and  the  count  of  the  flying  stars,  his  most  lively  recollection 
being  of  their  occasional  colors,  which  in  exceptional  cases 
ranged  from  full  crimson  to  a  vivid  green.  The  count  on  this 
night  was  very  great,  but  the  number  which  enter  the  earth's  at- 
mosphere even  ordinarily  is  most  surprising;  for,  though  any 
single  observer  may  note  only  a  few  in  his  own  horizon,  yet, 
taking  the  world  over,  at  least  ten  millions  appear  every  night, 
and  on  these  special  occasions  very  many  more.  This  Novem- 
ber shower  comes  always  from  a  particular  quarter  of  the  sky, 
that  occupied  by  the  constellation  Leo,  but  there  are  others, 
such  as  that  of  August  10th  (which  is  annual),  in  which  the 


196  THE  NEW  ASTRONOMY. 

"  stars"  seem  to  be  shot  at  us  from  the  constellation  Perseus; 
and  each  of  the  numerous  groups  of  star-showers  is  now  known 
by  the  name  of  the  constellation  whence  it  seems  to  come,  so 
that  we  have  Perse-ids  on  August  10th,  Geminuls  on  December 
12th,  Lyrids,  April  20th,  and  so  on. 

The  great  November  shower,  which  is  coming  once  more  in 
this  century,  and  which  every  reader  may  hope  to  see  toward 
1899,  is  of  particular  interest  to  us  as  the  first  whose  movements 
were  subjected  to  analysis ;  for  it  has  been  shown  by  the  labors 
of  Professor  Newton,  of  Yale,  and  Adams,  of  Cambridge,  that 
these  shooting  stars  are  bodies  moving  around  the  sun  in  an 
orbit  which  is  completed  in  about  thirty-three  years.  It  is 
quite  certain,  too,  that  they  are  not  exhalations  from  the  earth's 
atmosphere,  but  little  solids,  invisible  till  they  shine  out  by  the 
light  produced  by  their  own  fusion.  Each,  then,  moves  on  its 
own  track,  but  the  general  direction  of  all  the  tracks  concurs ; 
and  though  some  of  them  may  conceivably  be  solidified  gases, 
we  should  think  of  them  not  as  gaseous  in  form,  but  as  solid 
shot,  of  the  average  size  of  something  like  a  cherry,  or  perhaps 
even  of  a  cherry-stone,  yet  each  an  independent  planetoid,  flying 
with  a  hundred  times  the  speed  of  a  rifle-bullet  on  its  separate 
way  as  far  out  as  the  orbit  of  Uranus ;  coming  back  three  times 
in  a  century  to  about  the  earth's  distance  from  the  sun,  and 
repeating  this  march  forever,  unless  it  happen  to  strike  the  at- 
mosphere of  the  earth  itself,  when  there  comes  a  sudden  flash  of 
fire  from  the  contact,  and  the  distinct  existence  of  the  little  body, 
which  may  have  lasted  for  hundreds  of  thousands  of  years,  is 
ended  in  a  second. 

If  the  reader  will  admit  so  rough  a  simile,  we  may  compare 
such  a  flight  of  these  bodies  to  a  thin  swarm  of  swift-flying  birds 
—  thin,  but  yet  immensely  long,  so  as  to  be,  in  spite  of  the  rapid 
motion,  several  years  in  passing  a  given  point,  and  whose  line  of 
flight  is  cut  across  by  us  on  the  13th  of  November,  when  the 


METKORS.  197 

earth  passes  through  it.  We  are  only  there  on  that  day,  and 
can  only  see  it  then ;  but  the  swarm  is  years  in  all  getting  by, 
and  so  we  may  pass  into  successive  portions  of  it  on  the  anni- 
versary of  the  same  day  for  years  to  come.  The  stars  appear  to 
si  loot  from  Leo,  only  because  that  constellation  is  in  the  line  of 
their  flight  when  we  look  up  to  it,  just  as  an  interminable  train 
of  parallel  flying  birds  would  appear  to  come  from  some  definite 
point  on  the  horizon. 

We  can  often  see  the  flashes  of  meteors  at  over  a  hundred 
miles,  and  though  at  times  they  may  seem  to  come  thick  as 
flakes  of  falling  snow,  it  is  probable,  according  to  Professor 
Newton,  that  even  in  a  "  shower"  each  tiny  planetoid  is  more 
than  ten  miles  from  its  nearest  neighbor,  while  on  the  average  it 
is  reckoned  that  we  may  consider  that  each  little  body,  though 
possibly  no  larger  than  a  pea,  is  over  two  hundred  miles  from 
its  neighbor,  or  that  to  each  such  grain  there  is  nearly  ten 
million  cubic  miles  of  void  space.  Their  velocity  as  com- 
pounded with  that  of  the  earth  is  enormous,  sometimes  forty 
to  fifty  miles  per  second  (according  to  a  recent  but  unproved 
theory  of  Mr.  Denning,  it  would  be  much  greater),  and  it  is 
this  enormous  rate  of  progress  that  affords  the  semblance  of  an 
abundant  fall  of  rain,  notwithstanding  the  distance  at  which  one 
drop  follows  another.  It  is  only  from  their  light-  that  we  are 
able  to  form  a  rough  estimate  of  their  average  size,  which  is,  as- 
we  have  seen,  extremely  small ;  but,  from  their  great  number, 
the  total  weight  they  add  to  the  earth  daily  may  possibly  be  a 
hundred  tons,  probably  not  very  much  more.  As  they  are  as 
a  rule  entirely  dissipated  in  the  upper  air,  often  at  a  height  of 
from  fifty  to  seventy  miles,  it  follows  that  many  tons  of  the 
finest  pulverized  and  gaseous  matter  are  shot  into  the  earth's  at- 
mosphere every  twenty-four  hours  from  outer  space,  so  that  here 
is  an  independent  and  constant  supply  of  dust,  which  we  may 
expect  to  find  coming  down  from  far  above  the  highest  clouds. 


198  THE  NEW  ASTRONOMY. 

Now,  when  the  reader  sees  the  flash  of  a  shooting  star,  he 
may,  if  he  please,  think  of  the  way  the  imagination  of  the  East 
accounts  for  it,  or  he  may  look  at  what  science  has  given  him 
instead.  In  the  latter  case  he  will  know  that  a  light  which 
flashed  and  faded  almost  together  came  from  some  strange  little 
entity  which  had  been  traversing  cold  and  vacant  space  for  un- 
told years,  to  perish  in  a  moment  of  more  than  fiery  heat ;  an 
enigma  whose  whole  secret  is  unknown,  but  of  which,  during 
that  instant  flash,  the  spectroscope  caught  a  part,  and  found  evi- 
dence of  the  identity  of  some  of  its  constituents  with  those  of  the 
observer's  own  body. 


VIT. 

COMETS. 

OF  comets,  the  Old  Astronomy  knew  that  they  came  to  the 
sun  from  great  distances  in  all  directions,  and  in  calculable 
orbits ;  but  as  to  what  they  were,  this,  even  in  the  childhood  of 
those  of  us  who  are  middle-aged,  was  as  little  known  as  to  the 
centuries  during  which  they  still  from  their  horrid  heads  shook 
pestilence  and  wart  We  do  not  know  even  now  by  any  means 
exactly  what  they  are,  for  enough  yet  remains  to  be  learned 
about  them  still  to  give  their  whole  study  the  attraction  which 
belongs  to  the  unknown ;  and  yet  we  learn  so  much,  and  in  a 
way  which  to  our  grandfathers  would  have  been  so  unexpected, 
connecting  together  the  comet,  the  shooting  star,  and  the  mete- 
orite, that  the  astronomer  who  perhaps  speaks  with  most  author- 
ity about  these  to-day  was  able,  not  long  ago,  in  beginning  a 
lecture,  to  state  that  he  held  in  his  hand  what  had  been  a  part 
of  a  comet ;  and  what  he  held  was,  not  something  half  vaporous 
or  gaseous,  as  we  might  suppose  from  our  old  associations,  but  a 
curious  stone  like  this  on  page  203,  which,  with  others,  had 
fallen  from  the  sky  in  Iowa,  a  flashing  prodigy,  to  the  terror 
of  barking  dogs,  shying  horses,  and  fearful  men,  followed  by 
clouds  of  smoke  and  vapor,  and  explosions  that  shook  the  houses 
like  an  earthquake,  and  "  hollow  bello wings  and  rattling  sounds^ 
mingled  with  clang  and  clash  and  roar,"  as  an  auditor  described 
it.  It  is  only  a  fragment  of  a  larger  stone  which  may  have 
weighed  tons.  It  looks  inoffensive  enough  now,  and  its  appear- 


200  THE  NEW  ASTRONOMY. 

ance  affords  no  hint  of  the  commotion  it  caused  in  a  peaceable 
neighborhood  only  ten  years  ago.  13ut  what,  it  may  be  asked, 
is  the  connection  between  such  things  and  comets  ? 

To  answer  this,  let  us  recall  the  statement  that  the  orbit  of 
the  November  meteor  swarm  has  been  computed ;  which  means 
that  those  flying  bodies  have  been  found  to  come  only  from  one 
particular  quarter  out  of  all  possible  quarters,  at  one  particular 
angle  out  of  all  possible  angles,  at  one  particular  velocity  out  of 
all  possible  velocities,  and  so  on ;  so  that  the  chances  are  endless 
against  mere  accident  producing  another  body  which  agreed  in 
all  these  particulars,  and  others  besides.  Now,  in  1867  the  re- 
markable fact  was  established  that  a  comet  seen  in  the  previous 
year  (Comet  1,  1866)  had  the  same  orbit  as  the  meteoroids, 
which  implies,  as  we  have  just  seen,  that  the  comet  and  the 
meteors  were  in  some  way  closely  related. 

The  paths  of  the  August  meteors  and  of  the  Lyrids  also  have 
both  been  found  to  agree  closely  with  those  of  known  comets, 
and  there  is  other  evidence  which  not  only  connects  the  comets 
and  the  shooting  stars,  and  makes  it  probable  that  the  latter  are 
due  to  some  disintegration  of  the  former,  but  even  looks  as 
though  the  process  were  still  going  on.  And  now  with  this  in 
mind  we  may,  perhaps,  look  at  these  drawings  with  more 
interest. 

We  have  all  seen  a  comet,  and  we  have  all  felt,  perhaps, 
something  of  the  awe  which  is  called  up  by  the  thought  of  its 
immensity  and  its  rush  through  space  like  a  runaway  star.  Its 
head  is  commonly  like  a  small  luminous  point,  from  which 
usually  grows  as  it  approaches  the  sun  a  relatively  enormous 
brush  or  tail  of  pale  light,  which  has  sometimes  been  seen  to 
stretch  across  the  whole  sky  from  zenith  to  horizon.  It  is  use- 
less to  look  only  along  the  ecliptic  road  for  a  comet's  coming ; 
rather  may  we  expect  to  see  it  rushing  down  from  above,  or  up 
from  below,  sometimes  with  a  speed  which  is  possibly  greater 


1     « 
I     s 

c       §8 


CALIF  OF 


COMETS. 


203 


than  it  could  get  from  any  fall  —  not  so  much,  that  is,  the  speed 
of  a  body  merely  dropping  toward  the  sun  by  its  weight,  as 
that  of  a  missile  hurled  into  the  orderly  solar  system  from  some 
unknown  source  without,  and  also  associated  with  some  un- 
known power ;  for  while  it  is  doubtful  whether  gravity  is  suffi- 
cient to  account  for  the  velocity  of  all  comets,  it  seems  certain 
that  gravity  can  in  no  way  ex- 
plain some  of  the  phenomena  of 
their  tails. 

Thousands  of  comets  have 
been  seen  since  the  Christian 
era,  and  the  orbits  of  hundreds 
have  been  calculated  since  the 
time  of  Newton.  Though  they 
may  describe  any  conic  section, 
and  though  most  orbits  are 
spoken  of  as  parabolas,  this  is 
rather  a  device  for  the  analyst's 
convenience  than  the  exact  rep- 
resentation of  fact.  Without 
introducing  more  technical  lan- 
guage, it  will  be  enough  to  say 
here  that  we  learn  in  other  cases 

from  the  form  of  the  orbit  whether  the  body  is  drawn  essen- 
tially by  the  sun's  gravity,  or  whether  it  has  been  thrown 
into  the  system  by  some  power  beyond  the  sun's  control,  to 
pass  away  again,  out  of  that  control,  never  to  return.  It 
must  be  admitted,  however,  that  though  several  orbits  are  so 
classed,  there  is  not  any  one  known  to  be  beyond  doubt  of 
this  latter  kind,  while  we  are  certain  that  many  comets,  if  not 
all,  are  erratic  members  of  the  solar  family,  coming  back 
again  after  their  excursions,  at  regular,  though  perhaps  enor- 
mous, intervals. 


FIG.    81.  —  "A    PART   OF   A   COMET." 


204  THE  NEW  ASTRONOMY. 

But  what  we  have  just  been  saying*  belongs  rather  to  the 
province  of  the  Old  Astronomy  than  the  New,  Avhich  concerns 
itself  more  with  the  nature  and  appearance  of  the  heavenly 
bodies  than  the  paths  they  travel  on.  Perhaps  the  best  way  for 
us  to  look  at  comets  will  be  to  confine  our  attention  at  first  to 
some  single  one,  and  to  follow  it  from  its  earliest  appearance 
to  its  last,  by  the  aid  of  pictures,  and  thus  to  study,  as  it  were, 
the  species  in  the  individual.  The  difficulty  will  be  one  which 
arises  from  the  exquisitely  faint  and  diaphanous  appearance  of 
the  original,  which  no  ordinary  care  can  possibly  render,  though 
here  the  reader  has  had  done  for  him  all  that  the  wood-engraver 
can  do. 

We  will  take  as  the  subject  of  our  illustration  the  beautiful 
comet  which  those  of  us  who  are  middle-aged  can  remember 
seeing  in  1858,  and  which  is  called  Donati's  from  the  name  of  its 
discoverer.  We  choose  this  one  because  it  is  the  subject  of  an 
admirable  monograph  by  Professor  Bond  of  the  Harvard  College 
Observatory,  from  which  our  engravings  have,  by  permission, 
been  made. 

Let  us  take  the  history  of  this  comet,  then,  as  a  general  type 
of  others;  and  to  begin  at  the  beginning,  we  must  make  the 
very  essential  admission  that  the  origin  of  the  comet's  life  is  un- 
known to  us.  Where  it  was  born,  or  how  it  was  launched  on  its 
eccentric  path,  we  can  only  guess,  but  do  not  know ;  and  how 
long  it  has  been  traversing  it  we  can  only  tell  later.  On  the 
2d  of  June,  1858,  this  one  was  discovered  in  the  way  most  com- 
ets are  found,  that  is,  by  a  comet-hunter,  who  detected  it  as  a 
telescopic  speck  long  before  it  became  visible  to  the  naked  eye, 
or  put  forth  the  tail  which  was  destined  to  grow  into  the  beau- 
tiful object  many  of  us  can  remember  seeing.  For  over  a  cen- 
tury now  there  has  been  probably  no  year  in  which  the  heavens 
have  not  been  thus  searched  by  a  class  of  observers  who  make 
comet-hunting  a  specialty. 


COMETS.  207 

The  father  of  this  very  valuable  class  of  observers  appears  to 
have  been  Messier,  a  Frenchman  of  the  last  century  and  of  the 
purest  type  of  the  comet-hunters,  endowed  by  Nature  with  the 
instinct  for  their  search  that  a  terrier  has  for  rats.  In  that 
grave  book,  Delambre's  "  History  of  Astronomy,"  as  we  plod 
along  its  dry  statements  and  through  its  long  equations,  we 
find,  unexpected  as  a  joke  in  a  table  of  logarithms,  the  following 
piece  of  human  nature  (quoted  from  Messier's  contemporary, 
La  Harpe)  :  — 

"  He  [Messier]  has  passed  his  life  in  nosing  out  the  tracks  of  comets. 
He  is  a  very  worthy  man,  with  the  simplicity  of  a  baby.  Some  years  ago 
he  lost  his  wife,  and  his  attention  to  her  prevented  him  from  discovering 
a  comet  he  was  on  the  search  for,  and  which  Montaigne  of  Limoges  got 
away  from  him.  He  was  in  despair.  When  he  was  condoled  with  on 
the  loss  he  had  met,  he  replied,  with  his  head  full  of  the  comet,  '  Oh, 
dear!  to  think  that  when  I  had  discovered  twelve,  this  Montaigne 
should  have  got  my  thirteenth.'  And  his  eyes  filled  with  tears,  till, 
remembering  what  it  was  he  ought  to  be  weeping  for,  he  moaned, '  Oh, 
my  poor  wife ! '  but  went  on  crying  for  his  comet." 

Messier's  scientific  posterity  has  greatly  multiplied,  and  it  is 
rare  now  for  a  comet  to  be  seen  by  the  naked  eye  before  it  has 
been  caught  by  the  telescope  of  one  of  these  assiduous  searchers. 
Donati  had,  as  we  see,  observed  his  some  months  before  it  be- 
came generally  visible,  and  accordingly  the  engraving  on  page 
201  shows  it  as  it  appeared  on  the  evening  of  September  16, 
1858,  when  the  tail  was  already  formed,  and,  though  small,  was 
distinct  to  the  naked  eye,  near  the  stars  of  the  Great  Bear.  The 
reader  will  easily  recognize  in  the  plate  the  familiar  "  dipper,"  as 
the  American  child  calls  it,  where  the  leading  stars  are  put  down 
with  care,  so  that  he  may,  if  he  please,  identify  them  by  com- 
parison with  the  originals  in  the  sky,  even  to  the  little  companion 
to  Mizar  (the  second  in  the  handle  of  the  "  dipper,"  and  which 
the  Arabs  say  is  the  lost  Pleiad).  We  would  suggest  that  he 


208  THE  NEW  ASTRONOMY. 

should  note  botli  the  length  of  the  tail  on  this  evening  as  coin- 
pared  with  the  space  between  any  two  stars  of  the  "dipper" 
(for  instance,  the  two  right-hand  ones,  called  the  "pointers") 
and  its  distance  from  them,  and  then  turn  to  page  209,  where 
we  have  the  same  comet  as  seen  a  little  over  a  fortnight  later, 
on  October  3d.  Look  first  at  its  new  place  among  the  stars. 
The  "dipper"  is  still  in  view,  but  the  comet  has  drifted  awav 
from  it  toward  the  left  and  into  other  constellations.  The  large 
star  close  to  the  left  margin  of  the  plate,  with  three  little  stars 
below  and  to  the  right,  is  Arcturus ;  and  the  western  stars  of 
the  Northern  Crown  are  just  seen  higher  up.  Fortunately  the 
"  pointers,"  with  which  we  compared  the  comet  on  September 
16th,  are  still  here,  and  we  can  see  for  ourselves  how  it  has  not 
only  shifted  but  grown.  The  tail  is  three  times  as  long  as 
before.  It  is  rimmed  with  light  on  its  tipper  edge,  and  fades 
away  so  gradually  below  that  one  can  hardly  say  where  it  ends. 
But,  —  wonderful  and  incomprehensible  feature  !  —  shot  out  from 
the  head,  almost  as  straight  as  a  ray  of  light  itself,  but  fainter 
than  the  moonbeam,  now  appears  an  extraordinary  addition,  a 
sort  of  spur,  which  we  can  hardly  call  a  new  tail,  it  is  so  unlike 
the  old  one,  but  which  appears  to  have  been  darted  out  into 
space  as  if  by  some  mysterious  force  acting  through  the  head 
itself.  What  the  spur  is,  what  the  tail  is,  even  what  the  nucleus 
is,  we  cannot  be  said  really  to  know  even  to-day ;  but  of  the  tail 
and  of  the  nucleus  or  speck  in  the  very  head  of  the  comet  (too 
small  to  be  visible  in  the  engraving),  we  may  say  that  the  hairy 
tail  (comes)  gives  the  comet  its  name,  and  is  the  comet  to  popu- 
lar apprehension,  but  that  it  is  probably  the  smallest  part  of  the 
whole  mass,  while  the  little  shining  head,  which  to  the  telescope 
presents  a  still  smaller  speck  called  the  nucleus,  contains,  it  now 
seems  probable,  the  only  element  of  possible  danger  to  the  earth. 
While  admitting  our  lack  of  absolute  knowledge,  we  may,  if 
we  agree  that  meteorites  were  once  part  of  a  comet,  say  that  it 


y 

'     '^ 


COMETS.  211 

now  seems  probable  that  the  nucleus  is  a  hard,  stone-like  mass, 
or  collection  of  such  masses,  which  comes  from  " space"  (that 
is,  from  we  don't  know  how  far)  to  the  vicinity  of  the  sun,  and 
there  is  broken  by  the  heat  as  a  stone  in  a  hot  fire.  (Sir  Isaac 
Xewton  calculates,  in  an  often  quoted  passage  of  the  Principia, 
that  the  heat  which  the  comet  of  1680  was  subjected  to  in  its 
passage  by  the  sun  was  two  thousand  times  that  of  red-hot 
iron.)  We  have  seen  the  way  in  which  meteoric  stones  actually 
do  crack  in  pieces  with  heat  in  our  own  atmosphere,  partly, 
perhaps,  from  the  expansion  of  the  gases  the  stone  contains,  and 
it  seems  entirely  reasonable  to  suppose  that  they  may  do  so 
from  the  heat  of  the  sun,  and  that  the  escaped  gases  may  con- 
tribute something  toward  the  formation  of  the  tail,  which  is 
always  turned  away  from  the  sun,  and  which  always  grows 
larger  as  that  is  approached,  and  smaller  as  it  is  receded  from. 
However  this  may  be,  there  is  no  doubt  that  the  original  solid 
which  we  here  suppose  may  form  the  nucleus  is  capable  of  mis- 
chief, for  it  is  asserted  that  it  often  passes  the  earth's  orbit  with 
a  velocity  of  as  much  as  one  hundred  times  that  of  a  cannon- 
ball  ;  that  is,  with  ten  thousand  times  the  destructive  capacity  of 
a  ball  of  the  same  weight  shot  from  a  cannon. 

One  week  later,  October  9th,  the  comet  had  passed  over  Arc- 
turns  with  a  motion  toward  our  left  into  a  new  region  of  the 
sky,  leaving  Arcturus,  which  we  can  recognize  with  the  upper 
one  of  its  three  little  companions,  on  the  right.  Above  it  is  the 
whole  sickle  of  the  Northern  Crown,  and  over  these  stars  the  ex- 
tremity of  the  now  lengthened  tail  was  seen  to  spread,  but  with 
so  thin  a  veil  that  no  art  of  the  engraver  can  here  adequately 
represent  its  faintness.  The  tail  then,  as  seen  in  the  sky,  was 
now  nearly  twice  its  former  size,  though  for  the  reason  men- 
tioned it  may  not  appear  so  in  our  picture.  It  should  be  under- 
stood, too,  that  even  the  brightest  parts  of  the  original  were  far 
fainter  than  they  seem  here  in  comparison  with  the  stars,  which 


212  THE  NEW  ASTROXOMY. 

in  the  sky  are  brilliant  points  of  light,  which  the  engraver  can 
only  represent  by  dots  of  the  whiteness  of  the  paper.  This 
being  observed,  it  will  be  better  understood  that  in  the  sky  itself 
the  faintest  stars  were  viewed  apparently  undimmtMl  through  the 
blighter  parts  of  the  comet,  while  we  can  but  faintly  trace  here 
another  most  faint  but  curious  feature,  a  division  of  the  tail  into 
faint  cross-bands  like  auroral  streamers,  giving  a  look  as  if  it 
were  yielding  to  a  wind,  which  folded  it  into  faint  ridges  like 
those  which  may  be  seen  in  the  smoke  of  a  steamer  as  it  lags  far 
behind  the  vessel.  In  fact,  when  we  speak  of  "  the  "  tail,  it  must 
be  understood,  as  M.  Faye  reminds  us,  to  be  in  the  same  sense 
that  we  speak  of  the  plume  of  smoke  that  accompanies  an  ocean 
steamer,  without  meaning  that  it  is  the  same  thing  which  we  are 
watching  from  night  to  night,  more  than  we  do  that  the  same 
smoke-particles  accompany  the  steamer  as  it  moves  across 
the  Atlantic.  In  both  cases  the  form  alone  probably  remains ; 
the  thing  itself  is  being  incessantly  dissipated  and  renewed. 
There  is  no  air  here,  and  yet  some  of  these  appearances  in  the 
original  almost  suggest  the  idea  of  medium  inappreciably  thin 
as  compared  witli  the  head  of  the  comet,  but  whose  resistance  is 
seen  in  the  more  unsubstantial  tail,  as  that  is  drawn  through  it 
and  bent  backward,  as  if  by  a  wind  blowing  toward  the  celestial 
pole. 

The  most  notable  feature,  however,  is  the  development  of  a 
second  ray  or  spur,  which  has  been  apparently  darted  through 
millions  of  miles  in  the  interval  since  we  looked  at  it,  and  an 
almost  imperceptible  bending  backward  in  both,  as  if  they  too 
felt  the  resistance  of  something  in  what  we  are  accustomed  to 
think  of  as  an  absolute  and  perfect  void.  These  tails  are  a 
peculiarly  mysterious  feature.  They  are  apparently  shot  out 
in  a  direction  opposite  to  the  sun  (and  consequently  opposed 
to  the  direction  of  gravity)  at  the  rate  of  millions  of  miles  a 
day. 


COMETS.  215 

Beyond  the  fact  that  the  existence  of  some  repulsive  force  in 
the  sun,  a  "negative  gravity"  actually  existent,  not  in  fancy, 
but  in  fact,  seems  pointed  at,  astronomers  can  offer  little  but 
conjecture  here;  and  while  some  conceive  this  force  as  of  an 
electrical  nature,  others  strenuously  deny  it.  We  ought  to  ad- 
mit that  up  to  the  present  time  we  really  know  nothing  about  it, 
except  that  it  exists. 

At  this  date  (October  9th)  the  comet  had  made  nearly  its 
closest  approach  to  the  earth,  and  the  general  outline  has  been 
compared  to  that  of  the  wing  of  some  bird,  while  the  actual  size  was 
so  vast  that  even  at  the  distance  from  which  it  was  seen  it  filled 
an  angle  more  than  half  of  that  from  the  zenith  to  the  horizon. 

All  the  preceding  drawings  have  been  from  naked-eye  views ; 
but  if  the  reader  would  like  to  look  more  closely,  he  can  see  on 
page  217  one  taken  on  the  night  of  October  5th  through  the 
great  telescope  at  Cambridge,  Mass.  We  will  leave  this  to  tell 
its  own  story,  only  remarking  that  it  is  not  possible  to  reproduce 
the  phantom-like  faintness  of  the  original  spur,  here  also  dis- 
tinctly seen,  or  indeed  to  indicate  fairly  the  infinite  tenuity  of 
the  tail  itself.  Though  millions  of  miles  thick,  the  faintest  star 
is  yet  perceptibly  undimmed  by  it,  and  in  estimating  the  char- 
acter and  quantity  of  matter  it  contains,  after  noting  that  it  is 
not  self-luminous,  but  shines  only  like  the  moon  by  reflected 
sunlight,  we  may  recall  the  acute  observation  of  Sir  Isaac 
Newton  where  he  compares  the  brightness  of  a  comet's  tail  with 
that  of  the  light  reflected  from  the  particles  in  a  sunbeam  an 
inch  or  two  thick,  in  a  darkened  room,  and,  after  observing  that 
if  a  little  sphere  of  common  air  one  inch  in  diameter  were  rari- 
fied  to  the  degree  which  must  obtain  at  only  four  thousand  miles 
from  the  earth's  surface  it  would  fill  all  the  regions  of  the  planets 
to  far  beyond  the  orbit  of  Saturn,  suggests  the  excessively  small 
quantity  of  vapor  that  is  really  requisite  to  create  this  prodigious 
phantom. 


216  THE  SEW  ASTRONOMY. 

The  writer  has  had  occasion  for  many  years  to  make  a  special 
study  of  the  reflection  of  light  from  the  sky ;  and  if  such  studies 
may  authorize  him  to  express  any  opinion  of  his  own,  he  would 
give  his  adhesion  to  the  remark  of  Sir  John  Herschel,  that  the 
actual  weight  of  matter  in  such  a  cometary  tail  mny  be  con- 
ceivably only  an  affair  of  pounds  or  even  ounces.  But  if  this 
is  true  of  the  tail,  it  does  not  follow  of  the  nucleus,  just  seen  in 
this  picture,  but  of  which  the  engraving  on  page  2()f>  gives  a 
much  more  magnified  view.  It  is  a  sketch  of  the  head  alone, 
taken  from  a  telescopic  view  on  the  24th  of  September.  Here 
the  direction  of  the  comet  is  still  toward  the  sun  (which  must  be 
supposed  to  be  some  indefinite  distance  beyond  the  upper  part 
of  the  drawing),  and  we  see  that  the  lucid  matter  appears  to  be 
first  jetted  up,  and  then  forced  backward  on  either  side,  as  if  by 
a  wind  from  the  sun,  to  form  the  tail,  presenting  successive 
crescent-shaped  envelopes  of  decreasing  brightness,  which  are 
not  symmetrical,  but  one-sided,  while  sometimes  the  appearance 
is  that  of  spurts  of  luminous  smoke,  wavering  as  if  thrown  out 
of  particular  parts  of  the  internal  nucleus  "like  a  squib  not  held 
fast."  Down  the  centre  of  the  tail  runs  a  wonderfully  straight 
black  line,  like  a  shadow  cast  from  the  nucleus.  Only  the 
nucleus  itself  still  evades  us,  and  even  in  this,  the  most  mag- 
nified view  which  the  most  powerful  telescope  till  lately  in  ex- 
istence could  give,  remains  a  point. 

Considering  the  distance  of  the  comet  and  the  other  optical 
conditions,  this  is  still  perfectly  consistent  with  the  possibility 
that  it  may  have  an  actual  diameter  of  a  hundred  miles  or  more. 
It  "may"  have,  observe,  not  it  "has,"  for  in  fact  we  know  noth- 
ing about  it;  but  that  it  is  at  any  rate  less  than  some  few 
hundred  miles  in  diameter,  and  it  may,  for  anything  we  can 
positively  sav,  not  be  more  than  a  very  large  stone,  in  which 
case  our  atmosphere  would  probably  act  as  an  efficient  buffer  if 
it  struck  us;  or  it  may  have  a  mass  which,  coupled  with  its  ter- 


>4§S 
,       '^ 

rry 


COMETS.  219 

rible  speed,  would  cause  the  shock  of  its  contact  not  so  much  to 
pulverize  the  region  it  struck,  as  dissipate  it  and  everything  on 
it  instantly  into  vapor. 

Of  the  remarkable  investigations  of  the  spectroscope  on 
comets,  we  have  only  room  left  to  say  that  they  inform  us 
that  the  most  prominent  cometary  element  seems  to  be  carbon, 
-carbon,  which  Newton  two  hundred  years  before  the  spec- 
troscope, and  before  the  term  "  carbonic-acid  gas"  was  coined, 
by  some  guess  or  divination  had  described  in  other  words  as 
possibly  brought  to  us  by  comets  to  keep  up  the  carbonic-acid- 
gas  supply  in  our  air,  —  carbon,  which  we  find  in  our  own 
bodies,  and  of  which,  according  to  this  view,  the  comets  are 
original  sources. 

That  ^ve  may  be  partly  made  of  old  and  used-up  comets,  — 
surely  it  might  seem  that  a  madder  fancy  never  came  from  the 
brain  of  a  lunatic  at  the  full  of  the  moon! 

Science  may  easily  be  pardoned  for  not  giving  instant  recep- 
tion to  such  an  idea,  but  let  us  also  remember,  first,  that  it  is  a 
consequence  of  that  of  Sir  Isaac  Newton,  and  that  in  the  case 
of  such  a  man  as  he  we  should  not  be  hasty  to  think  we  un- 
derstand his  ignorance,  when  we  may  be  "  ignorant  of  his 
understanding ; "  and,  second,  that  it  has  been  rendered  at  least 
debatable  by  Dr.  Hunt's  recent  researches  whether  it  is  possible 
to  account  for  the  perennial  supply  of  carbon  from  the  earth's 
atmosphere,  without  looking  to  some  means  of  renewal  external 
to  the  planet. 

The  old  dread  of  comets  is  passing  away,  and  all  that  science 
has  to  tell  us  of  them  indicates  that,  though  still  fruitful  sources 
of  curiosity  and  indeed  of  wonder,  they  need  no  longer  be 
objects  of  terror.  Though  there  be,  as  Kepler  said,  more 
comets  in  the  sky  than  fish  in  the  ocean,  the  encounter  of 
the  earth  with  a  comet's  tail  would  be  like  the  encounter  with 
a  shadow,  and  the  chance  of  a  collision  with  the  nucleus  is 


THE  NEW  ASTRONOMY. 

remote  indeed.  We  may  sleep  undisturbed  even  if  a  new  comet 
is  announced  every  month,  though  it  is  true  that  here  as  else- 
where lie  remote  possibilities  of  evil. 

The  consideration  of  the  unfamiliar  powers  certainly  latent 
in  Nature,  such  as  belong  to  a  little  tremor  of  the  planet's  sur- 
face or  such  as  was  shown  in  that  scene  I  have  described,  when 
the  comparatively  insignificant  effect  of  the  few  tons  of  dynamite 
was  to  make  solid  buildings  unrealities,  which  vanished  away 
as  quickly  as  magic-lantern  pictures  from  a  screen,  may  help  us 
to  understand  that  the  words  of  the  great  poet  are  but  the  pos- 
sible expression  of  a  physical  fact,  and  that  "  the  cloud-capped 
towers,  the  gorgeous  palaces,  the  solemn  temples,"  —  and  we 
with  them,  —  may  indeed  conceivably  some  day  vanish  as  the 
airy  nothings  at  the  touch  of  Prosperous  wand,  and  without 
the  warning  to  us  of  a  single  instant  that  the  security  of  our 
ordinary  lives  is  about  to  be  broken.  We  concede  this,  how- 
ever, in  the  present  case  only  as  an  abstract  possibility ;  for  the 
advance  of  astronomical  knowledge  is  much  more  likely  to  show 
that  the  kernel  of  the  comet  is  but  of  the  bigness  of  some  large 
meteorite,  against  which  our  air  is  an  efficient  shield,  and  the 
chance  of  evil  is  in  any  case  most  remote,  —  in  any  case  only 
such  as  may  come  in  any  hour  of  our  lives  from  any  quarter, 
not  alone  from  the  earthquake  or  the  comet,  but  from  "the 
pestilence  that  walketh  in  darkness ; "  from  the  infinitely  little 
below  and  within  us,  as  well  as  from  the  infinite  powers  of 
the  universe  without. 


VIII. 

THE   STARS. 

IN  the  South  Kensington  Museum  there  is,  as  everybody 
knows,  an  immense  collection  of  objects,  appealing  to  all 
tastes  and  all  classes,  and  we  find  there  at  the  same  time  people 
belonging  to  the  wealthy  and  cultivated  part  of  society  lin- 
gering over  the  Louis  Seize  cabinets  or  the  old  majolica,  and 
the  artisan  and  his  wife  studying  the  statements  as  to  the  rela- 
tive economy  of  baking-powders,  or  admiring  Tippoo  Saib's 
wooden  tiger. 

There  is  one  shelf,  however,  which  seems  to  have  some 
attraction  common  to  all  social  grades,  for  its  contents  appear 
to  be  of  equal  interest  to  the  peer  and  the  costermonger.  It  is 
the  representation  of  a  man  resolved  into  his  chemical  elements, 
or  rather  an  exhibition  of  the  materials  of  which  the  human 
body  is  composed.  There  is  a  definite  amount  of  water,  for 
instance,  in  our  blood  and  tissues,  and  there  on  the  shelf  are 
just  so  many  gallons  of  water  in  a  large  vessel.  Another  jar 
shows  the  exact  quantity  of  carbon  in  us ;  smaller  bottles  con- 
tain our  iron  and  our  phosphorus  in  just  proportion,  while  others 
exhibit  still  other  constituents  of  the  body,  and  the  whole  reposes 
on  the  shelf  as  if  ready  for  the  coming  of  a  new  Frankenstein 
to  re-create  the  original  man  and  make  him  walk  about  again 
as  we  do.  The  little  vials  that  contain  the  different  elements 
which  we  all  bear  about  in  small  proportions  are  more  numer- 
ous, and  they  suggest,  not  merely  the  complexity  of  our  consti- 


222  THE  NEW  ASTRONOMY. 

tutions,  but  the  identity  of  our  elements  with  those  we  have 
found  by  the  spectroscope,  not  alone  in  the  sun,  but  even  in 
the  distant  stars  and  nebulae ;  for  this  wonderful  instrument  of 
the  New  Astronomy  can  find  the  traces  of  poison  in  a  stomach 
or  analyze  a  star,  and  its  conclusions  lead  us  to  think  that  the 
ancients  were  nearly  right  when  they  called  man  a  microcosm, 
or  little  universe.  We  have  literally  within  our  own  bodies 


FIG.  86.  —  TYPES  OF  STELLAR  SPECTRA. 


samples  of  the  most  important  elements  of  which  the  great 
universe  without  is  composed ;  and  you  and  I  are  not  only  like 
each  other,  and  brothers  in  humanity,  but  children  of  the  sun 
and  stars  in  a  more  literal  sense,  having  bodies  actually  made 
in  large  part  of  the  same  things  that  make  Sirius  and  Aldebaran. 
They  and  we  are  near  relatives. 

But  if  near  in  kind,  we  are  distant  relatives  in  another  way, 
for  the  sun,  whose  remoteness  we  have  elsewhere  tried  to  give 
an  idea  of,  is  comparatively  close  at  hand;  quite  at  hand,  one 
may  say,  for  if  his  distance,  which  we  have  found  so  enormous, 
be  represented  by  that  of  a  man  standing  so  close  beside  us  that 


THE  STARS.  223 


our  hand  may  rest  on  his  shoulder,  to  obtain  the  proportionate 
distance  of  one  of  the  nearest  stars,  like  Sirius,  for  instance,  we 
should  need  to  send  the  man  over  a  hundred  miles  away.  It  is 
probably  impossible  to  give  to  any  one  an  adequate  idea  of  the 
extent  of  the  sidereal  universe  ;  but  it  certainly  is  especially  hard 
for  the  reader  who  has  just  realized  with  difficulty  the  actual 
immensity  of  the  distance  of  the  sun,  and  who  is  next  told  that 
this  distance  is  literally  a  physical  point  as  seen  from  the  nearest 
star.  The  jaded  imagination  can  be  spurred  to  no  higher  flight, 
and  the  facts  and  the  enormous  numbers  that  convey  them  will 
not  be  comprehended. 

Look  down  at  one  of  the  nests  of  those  smallest  ants,  which 
are  made  in  our  paths.  To  these  little  people,  we  may  suppose, 
the  other  side  of  the  gravel  walk  is  the  other  side  of  the  world, 
and  the  ant  who  has  been  as  far  as  the  gate,  a  greater  traveller 
than  a  man  who  comes  back  from  the  Indies.  It  is  very  hard  to 
think  not  only  of  ourselves  as  relatively  far  smaller  than  such 
insects,  but  that,  less  than  such  an  ant-hill  is  to  the  whole  land- 
scape, is  our  solar  system  itself  in  comparison  with  the  new 
prospect  before  us ;  yet  so  it  is. 

All  greatness  and  littleness  are  relative.  When  the  traveller 
from  the  great  star  Sirius  (where,  according  to  the  author  of 
"  Micromegas,"  all  the  inhabitants  are  proportionately  tall  and 
proportionately  long-lived),  discovered  our  own  little  solar  sys- 
tem, and  lighted  on  what  we  call  the  majestic  planet  Saturn,  he 
was  naturally  astonished  at  the  pettiness  of  everything  com- 
pared with  the  world  he  had  left.  That  the  Saturnian  inhabi- 
tants were  in  his  eyes  a  race  of  mere  dwarfs  (they  were  only  a 
mile  high,  instead  of  twenty-four  miles  like  himself)  did  not 
make  them  contemptible  to  his  philosophic  mind,  for  he  reflected 
that  such  little  creatures  might  still  think  and  reason ;  but  when 
he  learned  that  these  puny  beings  were  also  correspondingly 
short-lived,  and  passed  but  fifteen  thousand  years  between  the 


224  THE  NEW  ASTRONOMY. 

cradle  and  the  grave,  lie  could  not  but  agree  that  this  was  like 
dying  as  soon  as  one  was  born,  that  their  life  was  but  a  span, 
and  their  globe  an  atom.  Yet  it  seems  that  when  one  of  these 
very  Saturnian  dwarfs  came  afterward  with  him  to  our  own  little 
ball,  and  by  the  aid  of  a  microscope  discovered  certain  animal- 
cule on  its  surface,  and  even  held  converse  with  two  of  them, 
he  could  not  in  turn  make  up  his  own  mind  that  intelligence 
could  inhere  in  such  invisible  insects,  till  one  of  them  (it  was  an 
astronomer  with  his"  sextant)  measured  his  height  to  an  inch,  and 
the  other,  a  divine,  expounded  to  him  the  theology  of  some  of 
these  mites,  according  to  which  all  the  heavenly  host,  including 
Saturn  and  Sirius  itself,  were  created  for  them. 

Do  not  let  us  hold  this  parable  as  out  of  place  here,  for  what 
use  is  it  to  write  down  a  long  series  of  figures  expressing  the 
magnitude  of  other  worlds,  if  it  leave  us  with  the  old  sense 
of  the  importance  to  creation  of  our  own ;  and  what  use  to 
describe  their  infinite  number  to  a  human  mite  who  reads,  and 
remains  of  the  opinion  that  he  is  the  object  they  were  all 
created  for! 

Above  us  are  millions  of  suns  like  ours.  The  Milky  Way 
(shown  on  page  225)  spreads  among  them,  vague  and  all- 
surrounding,  as  a  type  of  the  infinities  yet  unexplored,  and  of 
the  world  of  nebula?  of  which  we  still  know  so  little.  Let  us 
say  at  once  that  it  is  impossible  here  to  undertake  the  description 
of  the  discoveries  of  the  New  Astronomy  in  this  region,  for  we 
can  scarcely  indicate  the  headings  of  the  chapters  which  would 
need  to  be  written  to  describe  what  is  most  important. 

The  first  of  these  chapters  (if  we  treated  our  subjects  in  the 
order  of  distance)  would  be  one  on  space  itself,  and  our  changed 
ideas  of  the  void  which  separates  us  from  the  stars.  Of  this  we 
will  only  say  in  passing,  that  the  old  term  "the  temperature  of 
space  "  has  been  nearly  abrogated  ;  for  while  it  used  to  be  sup- 
posed that  more  than  half  of  the  heat  which  warmed  the  earth 


FIG.   87.  — THE   MILKY   WAY.       (FROM   A    STUDY   BY   E.    L.    TROUVELOT). 


*v?S^ 

J\>fr'*f     'W 

c  *w 


THE  STARS.  227 

came  from  this  mysterious  "space7'  or  from  the  stars,  it  is  now 
recognized  that  the  earth  is  principally  warmed  only  by  the  sun. 
Of  the  contents  of  the  region  between  the  earth  and  the  stars 
we  have,  it  must  be  admitted,  still  little  but  conjecture ;  though 
perhaps  that  conjecture  turns  more  than  formerly  to  the  idea  that 
the  void  is  not  a  real  void,  but  that  it  is  occupied  by  something 
which,  if  highly  attenuated,  is  none  the  less  matter,  and  some- 
thing other  and  more  than  the  mere  metaphysical  conception  of 
a  vehicle  to  transmit  light  to  us. 

( )f  the  stars  themselves,  we  should  need  another  chapter  to 
tell  what  has  been  newly  learned  as  to  their  color  and  light, 
even  by  the  old  methods,  that  is,  by  the  eye  and  the  telescope 
alone;  but  if  we  cannot  dwell  on  this,  we  must  at  least  refer, 
however  inadequately,  to  what  American  astronomers  are  doing 
in  this  department  of  the  New  Astronomy,  and  first  in  the  pho- 
tometry of  the  stars,  which  has  assumed  a  new  importance  of 
late  years,  owing  to  the  labors  carried  on  in  this  department  at 
Cambridge. 

That  one  star  differs  from  another  star  in  glory  we  have  long 
heard,  but  our  knowledge  of  physical  things  depends  largely  on 
our  ability  to  answer  the  question,  "  how  much?  "  and  the  value 
of  this  new  work  lies  in  the  accuracy  and  fulness  of  its  measures ; 
for  in  this  case  the  whole  heavens  visible  from  Cambridge  to 
near  the  southern  horizon  have  been  surveyed,  and  the  bright- 
ness of  every  naked-eye  star  repeatedly  measured,  so  that  all 
future  changes  can  be  noted.  This  great  work  has  taxed  the 
resources  of  a  great  observatory,  and  its  results  are  only  to  be 
adequately  valued  by  other  astronomers ;  but  Professor  Pick- 
ering's own  investigations  on  variable  stars  have  a  more  popular 
interest.  It  is  surely  an  amazing  fact  that  suns  as  large  or 
larger  than  our  own  should  seem  to  dwindle  almost  to  extinc- 
tion, and  regain  their  light  within  a  few  days  or  even  hours ; 
yet  the  fact  has  long  been  known,  while  the  cause  has  remained 


228  THE  NEW  ASTRONOMY. 

a  mystery.  A  mystery,  in  most  cases,  it  remains  still;  but  in 
some  we  have  begun  to  get  knowledge,  as  in  the  well-known 
instance  of  Algol,  the  star  in  the  head  of  Medusa.  Here  it  has 
always  been  thought  probable  that  the  change  was  due  to  some- 
thing coming  between  us  and  the  star;  but  it  is  on  this  very 
account  that  the  new  investigation  is  more  interesting,  as  show- 
ing how  much  can  be  done  on  an  old  subject  by  fresh  reasoning 
alone,  and  how  much  valuable  ore  may  lie  in  material  which  has 
already  been  sifted.  The  discussion  of  the  subject  by  Professor 
Pickering,  apart  from  its  elevated  aim,  has  if,  in  its  acute  analysis 
only,  the  interest  belonging  to  a  story  where  the  reader  first  sees 
a  number  of  possible  clews  to  some  mystery,  and  then  the 
gradual  setting  aside,  one  by  one,  of  those  which  are  only  loose 
ends,  and  the  recognition  of  the  real  ones  which  lead  to  the 
successful  solution.  The  skill  of  the  novelist,  however,  is 
more  apparent  than  real,  since  the  riddle  he  solves  for  us  is 
one  he  has  himself  constructed,  while  here  the  enigma  is  of 
Nature's  propounding;  and  if  the  solution  alone  were  given 
us,  the  means  by  which  it  is  reached  would  indeed  seem  to 
be  inexplicable. 

This  is  especially  so  when  we  remember  what  a  point  there 
is  to  work  on,  for  the  whole  system  reasoned  about,  though  if 
may  be  larger  than  our  own,  is  at  such  a  distance  that  it  ap- 
pears, literally  and  exactly,  far  smaller  to  the  eye  than  the  point 
of  the  finest  sewing-needle ;  and  it  is  a  course  of  accurate  rea- 
soning, and  reasoning  alone,  on  the  character  of  the  observed 
changing  brightness  of  this  point,  which  has  not  only  shown  the 
existence  of  some  great  dark  satellite,  but  indicated  its  size,  its 
(I Stance  from  its  sun,  its  time  of  revolution,  the  inclination  of 
its  orbit,  and  still  more.  The  existence  of  dark  invisible  bodies 
in  space,  then,  is  in  one  case  at  least  demonstrated,  and  in  this 
instance  the  dark  body  is  of  enormous  size;  for,  to  illustrate  by 
our  own  solar  system,  we  should  probably  have  to  represent  it 


THE  STARS.  229 

in  imagination  by  a  planet  or  swarm  of  planetoids  hundreds  of 
times  the  size  of  Jupiter,  and  (it  may  be  added)  whirling  around 
the  sun  at  less  than  a  tenth  the  distance  of  Mercury. 

Of  a  wholly  different  class  of  variables  are  those  which  have 
till  lately  only  been  known  at  intervals  of  centuries,  like  that 
new  star  Tycho  saw  in  1572.  I  infer  from  numerous  inquiries 
that  there  is  such  a  prevalent  popular  notion  that  the  "Star  of 
Bethlehem"  may  be  expected  to  show  itself  again  at  about  the 
present  time,  that  perhaps  I  may  be  excused  for  answering1  these 
questions  in  the  present  connection. 

In  the  first  place,  the  idea  is  not  a  new,  but  a  very  old  one, 
going-  back  to  the  time  of  Tycho  himself,  who  disputed  the 
alleged  identity  of  his  star  with  that  which  appeared  to  the  shep- 
herds at  the  Nativity.  The  evidence  relied  on  is,  that  bright 
stars  are  said  to  have  appeared  in  this  constellation  repeatedly  at 
intervals  of  from  three  hundred  and  eight  to  three  hundred  and 
nineteen  years  (though  even  this  is  uncertain) ;  and  as  the  mean 
of  these  numbers  is  about  three  hundred  and  fourteen,  which 
again  is  about  one-fifth  of  1572  (the  then  number  of  years  from 
the  birth  of  Christ),  it  has  been  suggested,  in  support  of  the  old 
notion,  that  the  Star  of  Bethlehem  might  have  been  a  variable, 
shining  out  every  three  hundred  and  fourteen  or  three  hundred 
and  fifteen  years,  whose  fifth  return  would  fall  in  with  the  ap- 
pearance that  Tycho  saw,  and  whose  sixth  return  would  come  in 
1886  or  1887.  This  is  all  there  is  about  it,  and  there  is  nothing 
like  evidence,  either  that  this  was  the  star  seen  by  the  Wise 
Men,  or  that  it  is  to  be  seen  again  by  us.  On  the  other  hand, 
nothing  in  our  knowledge,  or  rather  in  our  ignorance,  authorizes 
us  to  say  positively  it  cannot  come  again ;  and  it  may  be  stated 
for  the  benefit  of  those  who  like  to  believe  in  its  speedy  return, 
that  if  it  does  come,  it  will  make  its  appearance  some  night  in 
the  northern  constellation  of  Cassiopeia's  chair,  the  position 
originally  determined  by  Tycho  at  its  last  appearance,  being 


2oO  THE  NEW  ASTRONOMY. 

twenty-eight  degrees  and  thirteen  minutes  from  the  pole,  and 
twenty-six  minutes  in  right  ascension. 

We  were  speaking  of  these  new  stars  as  having  till  lately 
only  appeared  at  intervals  of  centuries ;  but  it  is  not  to  be  in- 
ferred that  if  they  now  appear  often er  it  is  because  there  are 
more  of  them.  The  reason  is,  that  there  are  more  persons  look- 
ing for  them;  and  the  fact  is  recognized  that,  if  we  have  ob- 
servers enough  and  look  closely  enough,  the  appearance  of 
" new  stars"  is  not  so  very  rare,  a  phenomenon.  Every  one  at 
all  interested  in  such  matters  remembers  that  in  1866  a  new  star 
broke  out  in  the  Northern  Crown  so  suddenly  that  it  was  shining 
as  bright  as  the  Polar  Star,  where  six  hours  before  there  had 
been  nothing  visible  to  the  eye.  Now  all  stars  are  not  as  large 
as  our  sun,  though  some  are  much  larger ;  but  there  are  circum- 
stances which  make  it  improbable  that  this  was  a  small  or  near 
object,  and  it  is  well  remembered  how  the  spectroscope  showed 
the  presence  of  abnormal  amounts  of  incandescent  hydrogen,  the 
material  which  is  perhaps  the  most  widely  diffused  in  the  uni- 
verse (and  which  is  plentiful,  too,  in  our  own  bodies),  so  that 
there  was  some  countenance  to  the  popular  notion  that  this  was 
a  world  in  flames.  We  were,  at  any  rate,  witnessing  a  catas- 
trophe which  no  earthly  experience  can  give  us  a  notion  of,  in  a 
field  of  action  so  remote  that  the  flash  of  light  which  brought  the 
news  was  unknown  years  on  the  way,  so  that  all  this  —  strange 
but  now  familiar  thought  —  occurred  long  before  we  saw  it 
happen.  The  star  faded  in  a  few  days  to  invisibility  to  the 
naked  eye,  though  not  to  the  telescope ;  and,  in  fact,  all  these 
phenomena  at  present  appear  rather  to  be  enormous  and  sudden 
enlargements  of  the  light  of  existing  bodies  than  the  creation  of 
absolutely  new  ones;  while  of  these  "  new  stars"  the  examples 
may  almost  be  said  to  be  now  growing  numerous,  two  having 
appeared  in  the  last  two  years. 

Not  to  enlarge,  then,  on  this  chapter  of  photometry,  let  us 


THE  STARS.  233 

add,  in  reference  to  another  department  of  stellar  astronomical 
work,  that  the  recognized  master  in  the  study  of  double  stars  the 
world  over  is  not  an  astronomer  by  profession,  at  the  head  of 
some  national  observatory  in  Berlin  or  Paris,  but  a  stenographer 
in  the  Chicago  law-courts,  Mr.  W.  S.  Burnham,  who,  after  his 
day's  duties,  by  nightly  labor,  prolonged  for  years  with  the  small 
means  at  an  amateur's  command,  has  perhaps  added  more  to  our 
knowledge  of  his  special  subject  in  ten  years  than  all  other  living 
astronomers. 

We  have  here  only  alluded  to  the  spectroscope  in  its  appli- 
cation to  stellar  research,  and  we  cannot  now  do  more  than  to 
note  the  mere  headlines  of  the  chapters  that  should  be  written 
on  it. 

First,  there  is  the  memorable  fact  that,  after  reaching  across 
the  immeasurable  distances,  we  find  that  the  stars  are  like  us,  — 
like  in  their  ultimate  elements  to  those  found  in  our  own  sun, 
our  own  earth,  our  own  bodies.  Any  fuller  view  of  the  subject 
than  that  which  we  here  only  indicate,  would  begin  with 
the  evidence  of  this  truth,  which  is  perhaps  on  the  whole  the 
most  momentous  our  science  has  brought  us,  and  with  which  no 
familiarity  should  lessen  our  wonder,  or  our  sense  of  its  deep 
and  permanent  significance.. 

Next,  perhaps,  we  should  understand  that,  invading  the  prov- 
ince of  the  Old  Astronomy,  the  spectroscope  now  tells  us  of  the 
motions  of  these  stars,  which  we  cannot  see  move,  —  motions  in 
what  we  have  always  called  the  " fixed"  stars,  to  signify  a  state 
of  fixity  to  the  human  eye,  which  is  such,  that  to  it  at  the  close 
of  the  nineteenth  century  they  remain  in  the  same  relative  posi- 
tions that  they  occupied  when  that  eye  first  looked  on  them,  in 
some  period  long  before  the  count  of  centuries  began. 

In  perhaps  the  earliest  and  most  enduring  work  of  man's 
hands,  the  great  pyramid  of  Egypt,  is  a  long  straight  shaft,  cut 
slopingly  through  the  solid  stone,  and  pointing,  like  a  telescope, 


THE  NEW  ASTRONOMY. 

to  the  heavens  near  the  pole.  If  we  look  through  it  now  we 
see  —  nothing;  but  when  it  was  set  up  it  pointed  to  a  particular 
star  which  is  no  longer  there.  That  pyramid  was  built  when 
the  savages  of  Britain  saw  the  Southern  Cross  at  night ;  and  the 
same  slow  change  in  the  direction  of  the  earth's  axis,  that  in 
thousands  of  years  has  borne  that  constellation  to  southern 
skies,  lias  carried  the  stone  tube  away  from  the  star  that  it 
once  pointed. at.  The  actual  motion  of  the  star  itself,  relatively 
to  our  system,  is  slower  yet,  —  so  inconceivably  slow  that  we 
can  hardly  realize  it  by  comparison  with  the  duration  of  the 
longest  periods  of  human  history.  The  stone  tube  was  pointed 
at  the  star  by  the  old  Egyptians,  but  "Egypt  itself  is  now  be- 
come the  land  of  obliviousness,  and  doteth.  Her  ancient  civility 
is  gone,  and  her  glory  hath  vanished  as  a  phantasm  a.  She 
poreth  not  upon  the  heavens,  astronomy  is  dead  unto  her,  and 
knowledge  maketh  other  cycles.  Canopus  is  afar  off,  Memnon 
resoundeth  not  to  the  Sun,  and  Nilus  heareth  strange  voices." 
In  all  this  lapse  of  ages,  the  star's  own  motion  could  not  have  so 
much  as  carried  it  across  the  mouth  of  the  narrow  tube.  Yet  a 
motion  to  or  from  us  of  this  degree,  so  slow  that  the  unaided  eye 
could  not  see  it  in  thousands  of  years  of  watching,  the  spectro- 
scope, first  efficiently  in  the  hands  of  the  English  astronomer, 
Dr.  Huggins,  and  later  in  those  of  Professor  Young  of  Princeton, 
not  only  reveals  at  a  look,  but  tells  us  the  amount  and  direction 
of  it,  in  a  way  that  is  as  strange  and  unexpected,  in  the  view  of 
our  knowledge  a  generation  ago,  as  its  revelation  of  the  essential 
composition  of  the  bodies  themselves. 

Again,  in  showing  us  this  composition,  it  has  also  shown  us 
more,  f6r  it  has  enabled  us  to  form  a  conjecture  as  to  the  relative 
ages  of  the  stars  and  suns ;  and  this  work  of  classifying  them, 
not  only  according  to  their  brightness,  but  each  after  his  kind, 
we  may  observe  was  begun  by  a  countryman  of  our  own,  Mr. 
Rutherfurd,  who  seems  to  have  been  among  the  first  after 


THE  STARS. 


235 


Fraunhofer  to  apply 
the  newly-invented  in- 
strument to  the  stars, 
and  quite  the  first  to 
recognize  that  these 
were,  broadly  speaking, 
divisible  into  a  few 
leading  types,  depend- 
ing" not  on  their  size 

o 

but  on  their  essential 
nature.  After  him  Sec- 
chi  (to  whom  the  first 
conception  is  often 
wrongly  attributed ) 
developed  it,  and  gave 
four  main  classes  into 
which  the  stars  are  in 
this  way  divisible,  a 
classification  which  has 
been  much  extended  by 
others;  while  the  first 
carefully  delineated 
spectra  were  those  of 
Dr.  Huggins,  who  has 
done  so  much  for  all 
departments  of  our  sci- 
ence that  in  a  fuller 
account  his  name  would 
reappear  in  every  chap- 
ter of  this  New  Astron- 
omy, and  than  whom 
there  is  no  more  emi- 
nent living  example  of 
its  study.  Owing  to 
their  feeble  light,  years 


236  THE  NEW  ASTRONOMY. 

were  needed  when  he  began  his  work  to  depict  completely  so 
full  a  single  spectrum  as  that  he  gives  of  Aldebaran,  though 
he  has  lived  to  see  stellar  spectrum  photography,  whose  use 
he  first  made  familiar,  producing  in  its  newest  development, 
which  we  give  here,  the  same  result  in  almost  as  many  min- 
utes. Before  we  present  this  latest  achievement  of  celestial 
photography,  let  us  employ  the  old  method  of  an  engraving 
made  from  eye-drawings,  once  more,  to  illustrate  on  page  "2 '2  "2 
the  distinct  character  of  these  spectra,  and  their  meaning.  In 
the  telespectroscope,  the  star  is  drawn  out  into  a  band  of  colored 
light,  but  here  we  note  only  in  black  and  white  the  lines  which 
are  seen  crossing  it,  the  red  end  in  these  drawings  being  at  the 
left,  and  the  violet  at  the  right;  and  we  may  observe  of  this 
illustration,  that  though  it  may  be  criticised  by  the  professional 
student,  and  though  it  lack  to  the  general  reader  the  attraction 
of  color,  or  of  beautiful  form,  it  is  yet  full  of  interest  to  any  one 
who  wishes  to  learn  the  meaning  of  the  message  the  star's  light 
can  be  made  to  yield  through  the  spectroscope,  and  to  know 
how  significant  the  differences  are  it  indicates  between  one  star 
and  another,  where  all  look  so  alike  to  the  eye.  First  is  the 
spectrum  of  a  typical  white  or  blue-white  star,  Sirius,  —  the  very 
brightest  star  in  the  sky,  and  which  we  all  know.  The  brighter 
part  of  the  spectrum  is  a  nearly  continuous  ribbon  of  color, 
crossed  by  conspicuous,  broad,  dark  lines,  exactly  corresponding 
in  place  to  narrower  ones  in  our  sun,  and  due  principally  to 
hydrogen.  Iron  and  magnesium  are  also  indicated  in  this  class, 
but  by  too  fine  lines  to  be  here  shown. 

Sirius,  as  will  be  presently  seen,  belongs  to  the  division  of 
stars  whose  spectrum  indicates  a  very  high  temperature,  and  in 
this  case,  as  in  what  follows,  we  may  remark  (to  use  in  part  Mr. 
Lockyer's  words)  that  one  of  the  most  important  distinctions 
between  the  stars  in  the  heavens  is  one  not  depending  upon 
their  mass  or  upon  anything  of  that  kind,  but  upon  conditions 


77//v  XT. I KS.  237 

which  make  their  spectra  differ,  just  in  the  way  that  in  our 
laboratories  the  spectrum  of  one  and  the  same  body  will  differ 
at  different  temperatures. 

What  these  absolutely  are  in  the  case  of  the  stars,  we  may 
not  know ;    but  placing  them  in  their  most  probable  relative 
order,   we  have  taken  as  an  instance  of  the   second  class,   or 
lower-temperature  stage,   our  own  sun.      The  impossibility  of 
giving  a  just  notion  of  its  real  complexity  may  be  understood, 
when  we  state  that  in  the  recent  magnificent  photographs  by 
Professor  Rowland,  a  part  alone  of  this  spectrum  occupies  some- 
thing like  fifty  times  the  space  here  given  to  the  whole,  so  that, 
crowded  with  lines  as  this  appears,  scarcely  one  in  fifty  of  those 
actually  visible  can  be  given  in  it.     Without  trying  to  under- 
stand all  these  now,   let  us   notice   only  the   identity  of  two 
or  three  of  its  principal   elements   with  those  found  in  other 
stars,  as  shown  by  the  corresponding  identity  of  some  leading 
lines.     Thus,  C  and  F  (with  others)  are  known  to  be  caused  by 
hydrogen ;    D,    by   sodium ;    &,    by   magnesium ;    while   fainter 
lines    are   given    by    iron    and    by   other    substances.      These 
elements  can  be  traced  by  their  lines  in  most  of  the  different 
star-spectra  on  this  plate,  and  all  those  named  are  constituents 
of  our  own  frames. 

The  hydrogen  lines  are  not  quite  accurately  shown  in  the 
plate  from  which  our  engraving  is  made,  those  in  Sirius,  for 
instance,  being  really  wider  by  comparison  than  they  are  here 
given ;  and  we  may  observe  in  this  connection,  that  by  the  par- 
ticular appearance  such  lines  wear  in  the  spectrum  itself  we  can 
obtain  some  notion  of  the  mass  of  a  star,  as  well  as  of  its  chemi- 
cal constitution.  We  can  compare  the  essential  characteristics 
of  such  bodies,  then,  without  reference  to  their  apparent  size,  or 
as  though  they  were  all  equally  remote  ;  and  it  is  a  striking 
thought,  that  when  we  thus  rise  to  an  impartial  contemplation 
of  the  whole  stellar  universe,  our  sun,  whose  least  ray  makes  the 


238  THE  NEW  ASTRONOMY. 

whole  host  of  stars  disappear,  is  found  to  be  not  only  itself  a 
star,  but  by  comparison  a  small  one,  —  one  at  least  which  is 
more  probably  below  than  above  the  average  individual  of  its 
class,  while  some,  such  as  Sirius,  are  not  impossibly  hundreds  of 
times  its  size. 

Then  comes  a  third  class,  such  as  is  showrn  in  the  spectrum  of 
the  brightest  star  in  Orion,  looking  still  a  little  like  that  of  our 
sun;  but  yet  more  distinctively  in  that  of  the  brightest  star  in 
Hercules,  looking  like  a  columnar  or  fluted  structure,  and  con- 
cerning which  the  observations  of  Lockyer  and  others  create  the 
strong  presumption,  not  to  say  certainty,  that  we  have  here  a 
lower  temperature  still.  Antares  and  other  reddish  stars  belong 
to  this  division,  which  in  the  very  red  stars  passes  into  the  fourth 
type,  and  there  are  more  classes  and  subclasses  without  end ;  but 
we  invite  here  attention  particularly  to  the  first  three,  much  as 
we  might  present  a  child,  an  adult,  and  an  old  man,  as  types  of 
the  stages  of  human  existence,  without  meaning  to  deny  that 
there  are  any  number  of  ages  between.  We  can  even  say  that 
this  may  be  something  more  than  a  mere  figure  of  speech, 
and  that  a  succession  in  age  is  not  improbably  pointed  at  in 
these  types. 

We  may  have  considered  —  perhaps  not  without  a  sort  of 
awe  at  the  vastness  of  the  retrospect  —  the  past  life  of  the 
worlds  of  our  own  system,  from  our  own  globe  of  fluid  fire  as 
we  see  it  by  analogy  in  the  past,  through  the  stages  of  plane- 
tary life  to  the  actual  condition  of  our  present  green  earth,  and 
on  to  the  stillness  of  the  moon.  Yet  the  life  history  of  our  sun, 
we  can  hardly  but  admit,  is  indefinitely  longer  than  this.  We 
feel,  rather  than  comprehend,  the  vastness  of  the  period  that 
separates  our  civilization  from  the  early  life  of  the  w^orld ;  but 
what  is  this  to  the  age  of  the  sun,  which  lias  looked  on  and  seen 
its  planetary  children  grow!  Yet  if  we  admit  this  temperature 
classification  of  the  stars,  we  are  not  far  from  admitting  that  the 


THK   N'/MA'X  241 

spectroscope  is  now  pointing  out  the  stages  in  the  life  of  suns 
themselves ;  suns  just  beginning  their  life  of  almost  infinite 
years  :  suns  in  the  middle  of  their  course;  suns  which  are  grow- 
ing old  and  casting  feebler  beams,  —  all  these  and  many  more  it 
brings  before  us. 

O 

Another  division  of  our  subject  would,  with- more  space,  in- 
clude a  fuller  account  of  that  strange  and  most  interesting 
development  of  photography  which  is  going  on  even  while  we 
write ;  and  this  is  so  new  and  so  important,  that  we  must  try  to 
give  some  hint  of  it  even  in  this  brief  summary,  for  even  since 
the  first  numbers  of  this  series  were  written,  great  advances  have 
taken  place  in  its  application  to  celestial  objects. 

Most  of  us  have  vague  ideas  about  small  portions  of  time  ;  so 
much  so,  that  it  is  rather  surprising  to  find  to  how  many  intel- 
ligent people,  a  second,  as  seen  on  the  clock  face,  is  its  least 
conceivable  interval.  Yet  a  second  has  not  only  a  beginning, 
middle,  and  end,  as  much  as  a  year  has,  but  can,  in  thought  at 
least,  be  divided  into  just  as  many  numbered  parts  as  a  year 
can.  Without  entering  on  a  disquisition  about  this,  let  us  try 
to  show  by  some  familiar  thing  that  we  can  at  any  rate  not 
only  divide  a  second  in  imagination  into,  let  us  say,  a  hundred 
parts,  but  that  we  can  observe  distinctly  what  is  happening  in 
such  a  short  time,  and  make  a  picture  of  it,  —  a  picture  which 
shall  be  begun  and  completed  while  this  hundredth  of  a  second 
lasts. 

Every  one  has  fallen  through  at  least  some  such  a  little  dis- 
tance as  comes  in  jumping  from  a  chair  to  the  floor,  and  most  of 
us,  it  is  safe  to  say,  have  a  familiar  impression  of  the  fact  that  it 
takes,  at  any  rate,  less  than  a  second  in  such  a  case  from  the 
time  the  foot  leaves  its  first  support  till  it  touches  the  ground. 
Plainly,  however  large  or  small  the  fall  may  be,  each  fraction  of 
an  inch  of  it  must  be  passed  through  in  succession,  and  if  we 
suppose  the  space  to  be  divided,  for  instance,  into  a  hundred 

16 


242  THE  NEW  ASTRONOMY. 

parts,  we  must  divide  in  thought  the  second  into  at  least  as 
many,  since  eacli  little  successive  space  was  traversed  in  its  own 
little  interval  of  time,  and  the  whole  together  did  not  make  a 
second.  We  can  even,  as  a  matter  of  fact,  very  easily  calculate 
the  time  that  it  will  take  anything  which  has  already  fallen,  let 
us  say  one  foot,  to  fall  an  inch  more ;  and  we  find  this,  in  the 
supposed  instance,  to  be  almost  exactly  one  one-hundredth  of  a 
second.  On  page  243  is  a  reproduction  of  a  photograph  from 
Nature,  of  a  man  falling  freely  through  the  air.  He  has  dropped 
from  the  grasp  of  the  man  above  him,  and  has  already  fallen 
through  some  small  distance,  —  a  foot  or  so.  If  we  suppose  it 
to  be  a  foot,  since  we  can  see  that  the  man's  features  are  not 
blurred,  as  they  would  undoubtedly  have  been  had  he  moved 
even  much  less  than  an  inch  while  this  picture  was  being  taken, 
it  follows,  from  what  has  been  said,  that  the  making  of  the  whole 
picture  —  landscape,  spectators,  and  all  —  occupied  not  over  one 
one-hundredth  of  a  second. 

We  have  given  this  view  of  "the  falling  man"  because, 
rightly  understood,  it  thus  carries  internal  evidence  of  the  limit 
of  time  in  which  it  could  have  been  made ;  and  this  will  serve  as 
an  introduction  to  another  picture,  where  probably  no  one  will 
dispute  that  the  time  was  still  shorter,  but  where  we  cannot  give 
the  same  kind  of  evidence  of  the  fact. 

"  Quick  as  lightning"  is  our  common  simile  for  anything  oc- 
cupying, to  ordinary  sense,  no  time  at  all.  Exact  measurements 
show  that  the  electric  spark  does  occupy  a  time,  which  is  almost 
inconceivably  small,  and  of  which  we  can  only  say  here  that  the 
one  one-hundredth  of  a  second  we  have  just  been  considering  is 
a  long  period  by  comparison  with  the  duration  of  the  brightest 
portion  of  the  light. 

On  page  245  we  have  the  photograph  of  a  flash  of  lightning 
(which  proves  to  be  several  simultaneous  flashes),  taken  last 
July  from  a  point  on  the  Connecticut  coast,  and  showing  not 


•/•///•;  .sy 


243 


FIG.    92. — A    FALT/ING    MAX. 


only  the  vivid  zigzag  streaks  of  the  lightning  itself,  but  some- 
thing of  the  distant  sea  view,  and  the  masts  of  the  coast  survey 
schooner  "Palinurus"  in  the  foreground,  relieved  against  the  sky. 
We  are  here  concerned  with  this  interesting  autograph  of  the 


244  THE  KK\Y  ASTRONOMY. 

lightning,  only  as  an  illustration  of  our  subject,  and  as  proving 
the  almost  infinite  sensitiveness  of  the  recent  photographic  pro- 
cesses; for  there  seems  to  be  no  limit  to  the  briefness  of  time 
in  which  these  can  so  act  in  some  degree,  whether  the  light 
be  bright  or  faint,  and  no  known  limit  to  the  briefness  of 
time  required  for  them  to  act  effectively  if  the  light  be  bright 
enough. 

What  has  just  preceded  will  now  help  us  to  understand  how 
it  is  that  photography  also  succeeds  so  well  in  the  incomparably 
fainter  objects  we  are  about  to  consider,  and  which  have  been 
produced  not  by  short  but  by  long  exposures.  We  have  just 
seen  how  sensitive  the  modern  plate  is,  and  we  are  next  to  notice 
a  new  and  very  important  point  in  which  photographic  action  in- 
general  differs  remarkably  from  that  of  the  eye.  Seeing  may  be 
described,  not  wholly  inaptly,  as  the  recognition  of  a  series  of 
brief  successive  photographs,  taken  by  the  optic  lens  on  the 
retina;  but  the  important  difference  between  seeing  and  photo 
graphing,  which  we  now  ask  attention  to,  is  this :  When  the  eye 
looks  at  a  faint  object,  such  as  the  spectrum  of  a  star,  or  at  the 
still  fainter  nebula,  this,  as  we  know,  appears  no  brighter  at 
the  end  of  half  an  hour  than  at  the  end  of  the  first  half-second. 
In  other  words,  after  a  brief  fraction  of  a  second,  the  visual  effect 
does  not  sensibly  accumulate.  But  in  the  action  of  the  photo- 
graph, on  the  contrary,  the  effect  does  accumulate,  and  in  the 
case  of  a  weak  light  accumulates  indefinitely.  It  is  owing  to 
this  precious  property,  that  supposing  (for  illustration  merely) 
the  lightning  flash  to  have  occupied  the  one-thousandth  part  of  a. 
second  in  impressing  itself  on  the  plate,  to  get  a  nearly  similar 
effect  from  a  continuous  light  one  thousand  times  weaker,  wre 
have  only  to  expose  the  plate  a  thousand  times  as  long,  that  is, 
for  one  second;  while  from  a  liirht  a  million  times  weaker  we 
should  get  the  same  result  by  exposing  it  a  million  times  as 
long,  that  is,  for  a  thousand  seconds. 


THE  STARS.  245 

And  now  that  we  come  to  the  stars,  whose  spectra  occupy 
minutes  in  taking1,  what  we  jnst  considered  will  help  us  to 
understand  how  we  can  advantageously  thus  pass  from*  a 
thousandth  of  a  second  or  less,  to  one  thousand  seconds  or 
even  more,  and  how  we  can  even,  —  given  time  enough,  — 


FIG.    !I3. A    FLASH    OF    LIGHTNING.       (FROM    A    PHOTOGRAPH    BY    DR.    II.    G.    FIFFARD.) 

conceivably,   be  able  to  photograph  what   the  eye  cannot  see 
at  all. 

We  have  on  page  231  a  photograph  quite  recently  taken  at 
Cambridge  from  a  group  of  stars  (the  Pleiades)  passing  by  the 
telescope.  Every  star  is  caught  as  it  goes,  and  presented,  not  in 
its  ordinary  appearance  to  the  eye,  but  by  its  spectrum.  There 
is  a  general  resemblance  in  these  spectra  from  the  same  cluster; 
while  in  other  cases  the  spectra  are  of  all  types  and  kinds,  the 
essential  distinction  between  individuals  alike  to  the  eve,  being 


246  THE  NEW  ASTRONOMY. 

more  strikingly  shown,  as  stars  apparently  far  away  from 
another  are  seen  to  have  a  common  nature,  and  stars  looking 
close  together  (but  which  may  be  merely  in  line,  and  really  far 
apart)  have  often  no  resemblance;  and  so  the  whole  procession 
passes  through  the  field  of  view,  each  individual  leaving  its  own 
description.  This  self-description  will  be  better  seen  in  the  re- 
markable photographs  of  the  spectra  of  Vega  and  Aldebaran, 
which  are  reproduced  on  page  235  from  the  originals  by  a  pro- 
cess independent  of  the  graver.  They  were  obtained  on  the 
night  of  November  9,  1886,  at  Cambridge,  as  a  part  of  the  work 
pursued  by  Professor  Pickering,  with  means  which  have  been 
given  from  fitting  hands,  thus  to  form  a  memorial  of  the  late  Dr. 
Henry  Draper.  We  are  obliged  to  the  source  indicated,  then, 
for  the  ability  to  show  the  reader  here  the  latest,  and  as  yet  in- 
edited,  results  in  this  direction ;  and  they  are  such  as  fully  to 
justify  the  remark  made  above,  that  minutes,  by  this  new  pro- 
cess, take  the  place  of  years  of  work  by  the  most  skilful  astrono- 
mer's eye  and  hand. 

The  spectrum  of  Vega  (Alpha  Lyrse)  is  marked  only  by  a 
few  strong  lines,  due  chiefly  to  hydrogen,  because  these  are  all 
there  are  to  be  seen  in  a  star  of  its  class.  Aldebaran  (the  bright 
star  in  Taurus),  on  the  contrary,  here  announces  itself  as  belong- 
ing to  the  family  of  our  own  sun,  a  probably  later  type,  and  dis- 
tinguished by  solar-like  lines  in  its  spectrum,  which  may  be 
counted  in  the  original  photograph  to  the  number  of  over  two 
hundred.  There  is  necessarily  some  loss  in  the  printed  repro- 
duction ;  but  is  it  not  a  wonderful  thing,  to  be  able  to  look  up, 
as  the  reader  may  do,  to  Aldebaran  in  the  sky,  and  then  down 
upon  the  page  before  us,  knowing  that  that  remote,  trembling 
speck  of  light  has  by  one  of  the  latest  developments  of  the  New 
Astronomy  been  made,  without  the  intervention  of  the  graver's 
hand,  to  write  its  own  autograph  record  on  the  page  before 
him) 


Tin-:  STARS.  247 

In  the  department  of  nebular  astronomy,  photography  has 
worked  an  equal  change.  The  writer  well  remembers  the  weeks 
he  has  himself  spent  in  drawing  or  attempting  to  draw  nebulae,  - 
things  often  so  ghost-like  as  to  disappear  from  view  every  time 
the  eye  turned  from  the  white  paper,  and  only  to  be  seen  again 
when  it  had  recovered  its  sensitiveness  by  gazing  into  the  dark- 
ness.  The  labors  of  weeks  were,  literally,  only  represented  by 
what  looked  like  a  stain  on  the  paper ;  and  no  two  observers, 
however  careful,  could  be  sure  that  the  change  between  two 
drawings  of  a  nebula  at  different  dates  was  due  to  an  alteration 
in  the  thing  itself,  or  in  the  eye  or  hand  of  the  observer,  though 
unfortunately  for  the  same  reason  it  is  impossible  fully  to  render 
the  nebulous  effect  of  the  photograph  in  engraving.  We  cannot 
with  our  best  efforts,  then,  do  full  justice  to  the  admirable  one 
of  Orion,  on  page  239,  which  we  owe  to  the  particular  kind- 
ness of  Mr.  Common,  of  Earing,  England,  whose  work  in  this 
field  is  as  yet  unequalled.  The  original  enlargement  measures 
nearly  two  square  feet  in  area,  with  fine  definition.  It  is 
taken  by  thirty-nine  minutes'  exposure,  and  its  character  can 
only  be  indicated  here ;  for  it  is  not  too  much  to  say  here 
of  this  original  also,  that  as  many  years  of  the  life  of  the  most 
skilled  artist  could  not  produce  so  trustworthy  a  record  of  this 
wonder. 

The  writer  remembers  the  interest  with  which  he  heard  Dr. 
1  )raper,  not  long  before  his  lamented  death,  speak  of  the  almost 
incredible  sensitiveness  of  these  most  recent  photographic  pro- 
••••sses,  and  his  belief  that  we  were  fast  approaching  the  time 
when  we  should  photograph  what  we  could  not  even  see.  That 
time  has  now  arrived.  At  Cambridge,  in  Massachusetts,  and  at 
the  Paris  Observatory,  by  taking  advantage  of  the  cumulative 
action  we  have  referred  to,  and  by  long  exposures,  photographs 
have  recently  been  taken  showing  stars  absolutely  invisible  to 
the  telescope,  and  enabling  us  to  discover  faint  nebula?  whose 


248  THE  NEW  ASTRONOMY. 

previous  existence  had  not  been  suspected ;  and  when  we  con- 
sider that  an  hour's  exposure  of  a  plate,  now  not  only  secures 
a  fuller  star-chart  than  years  of  an  astronomer's  labor,  but  a 
more  exact  one,  that  the  art  is  every  month  advancing-  per- 
ceptibly over  the  last,  and  that  it  is  already,  as  we  may  say, 
not  only  making  pictures  of  what  we  see,  but  of  what 
we  cannot  see  even  with  the  telescope,  —  we  have  before  us 
a  prospect  whose  possibilities  no  further  words  are  needed  to 
suggest. 

We  have  now,  not  described,  but  only  mentioned,  some  di- 
vision of  the  labors  of  the  New  Astronomy  in  its  photometric, 
spectroscopic,  and  photographic  stellar  researches,  on  each  of 
which  as  many  books,  rather  than  chapters,  might  be  written,  to 
give  only  what  is  novel  and  of  current  interest.  But  these  are 
themselves  but  a  part  of  the  modern  work  that  has  overturned 
or  modified  almost  every  conception  about  the  stellar  universe 
which  was  familiar  to  the  last  generation,  or  which  perhaps  we 
were  taught  in  our  own  youth. 

In  considering  the  results  to  be  drawn  from  this  glance  we 
have  taken  at  some  facts  of  modern  observation,  if  it  be  asked, 
not  only  what  the  facts  are,  but  what  lessons  the  facts  them- 
selves have  to  teach,  there  is  more  than  one  answer,  for  the 
moral  of  a  story  depends  on  the  one  who  draws  it,  and  A\e  may 
look  on  our  story  of  the  heavens  from  the  point  of  view  either 
of  our  own  importance  or  of  our  own  insignificance.  In  the  one 
case  we  behold  the  universe  as  a  sort  of  reflex  of  our  own 
selves,  mirroring  in  vast  proportions  of  time  and  space  our  own 
destiny ;  and  even  from  this  standpoint,  one  of  the  lessons  of  our 
subject  is  surely  that  there  is  no  permanence  in  any  created 
tiling.  When  primitive  man  learned  that  with  lapsing  years  the 
oak  withered  and  the  very  rock  decayed,  more  slowly  but  as 
surely  as  himself,  he  looked  up  to  the  stars  as  the  types  of 


777 /•;    STARS 

contrast  to  the  change  he  shared,  and  fondly  deemed  them 
eternal;  hut  now  we  have  found  change  there,  and  that  prob- 
ably the  star  clusters  and  the  nebulae,  even  if  clouds  of  suns 
and  worlds,  are  fixed  only  by  comparison  with  our  own  brief 
years,  and,  tried  by  the  terms  of  their  own  long  existence,  are 
fleeting  like  ourselves. 

••  We  have  often  witnessed  the  formation  of  a  cloud  in  a  serene  sky. 
A  lia/y  point  barely  perceptible  —  a  little  wreath  of  mist  increases  in 
volume  and  becomes  darker  and  denser,  until  it  obscures  a  large  portion 
of  the  heavens.  It  throws  itself  into  fantastic  shapes,  it  gathers  a  glory 
from  the  sun,  is  borne  onward  by  the  wind,  and  as  it  gradually  came,  so, 
perhaps,  it  gradually  disappears,  inciting  away  in  the  untroubled  air. 
I  Jut  the  universe  is  nothing  more  than  such  a  cloud,  —  a  cloud  of  suns 
ji nd  worlds.  Supremely  grand  though  it  may  seem  to  us,  to  the  infinite 
and  eternal  intellect  it  is  no  more  than  a  fleeting  mist.  If  there  be  a 
Miecession  of  worlds  in  infinite  space,  there  is  also  a  succession  of  worlds 
in  infinite  time.  As  one  after  another  cloud  replaces  clouds  in  the  skies, 
so  this  starry  system,  the  universe,  is  the  successor  of  countless  others 
that  have  preceded  it,  —  the  predecessor  of  countless  others  that  will 
follow." 

These  impressions  are  strengthened  rather  than  weakened 
when  we  come  back  from  the  outer  universe  to  our  own  little 
solar  system;  for  every  process  which  we  know,  tends  to  the 
dissipation,  or  rather  the  degradation,  of  heat,  and  seems  to 
point,  in  our  present  knowledge,  to  the  final  decay  and  extinc- 
tion of  the  light  of  the  world.  In  the  words  of  one  of  the  most 
eminent  living  students  of  our  subject,  "  The  candle  of  the  sun 
is  burning  down,  and,  as  far  as  we  can  see,  must  at  last  reach 
the  socket.  Then  will  begin  a  total  eclipse  which  wrill  have  no 
end. 

'  Dies  irse,  dies  ilia, 
Solvet  sseclum  in  tavilla.'" 

Yet  though  it  may  well  be  that  the  fact  itself  here  is  true,  it 
is  possible  that  we  draw  the  moral  to  it,  unawares,  from  an  un- 


250  THE  NEW  ASTRONOMY. 

acknowledged  satisfaction  in  the  idea  of  the  vastness  of  the 
funeral  pyre  provided  for  such  beings  as  ourselves,  and  that  it 
is  pride,  after  all,  which  suggests  the  thought  that  when  the 
sun  of  the  human  race  sets,  the  universe  will  be  left  tenantless, 
as  a  body  from  which  the  soul  lias  fled.  Can  we  not  bring  our- 
selves to  admit  that  there  may  be  something  higher  than  num 
and  more  enduring  than  frail  humanity,  in  some  sphere  in  which 
our  universe,  conditioned  as  it  is  in  space  and  time,  is  itself  em- 
braced ;  and  so  distrust  the  conclusions  of  man's  reason  where 
they  seem  to  flatter  his  pride  ? 

May  we  not  receive  even  the  teachings  of  science,  as  to  the 
"Laws  of  Nature,"  with  the  constant  memory  that  all  we  know, 
even  from  science  itself,  depends  on  our  very  limited  sensa- 
tions, our  very  limited  experience,  and  our  still  more  limited 
power  of  conceiving  anything  for  which  this  experience  lias 
not  prepared  us  ? 

I  have  read  somewhere  a  story  about  a  race  of  ephemeral 
insects  who  live  but  an  hour.  To  those  who  are  born  in  the 
early  morning  the  sunrise  is  the  time  of  youth.  They  die  of  old 
age  while  his  beams  are  yet  gathering  force,  and  only  their  de- 
scendants live  on  to  midday ;  while  it  is  another  race  which  sees 
the  sun  decline,  from  that  which  saw  him  rise.  Imagine  the  sun 
about  to  set,  and  the  whole  nation  of  mites  gathered  under  the 
shadow  of  some  mushroom  (to  them  ancient  as  the  sun  itself)  to 
hear  what  their  wisest  philosopher  has  to  say  of  the  gloomy 
prospect.  If  I  remember  aright,  he  first  told  them  that,  incred- 
ible as  it  might  seern,  there  was  not  only  a  time  in  the  world's 
youth  when  the  mushroom  itself  was  young,  but  that  the  sun  in 
those  early  ages  was  in  the  eastern,  not  in  the  western,  sky. 
Since  then,  he  explained,  the  eyes  of  scientific  ephemera  had  fol- 
lowed it,  and  established  by  induction  from  vast  experience  the 
great  "Law  of  Nature,"  that  it  moved  only  westward ;  and  he 


THE  STAXX.  251 

showed  that  since  it  was  now  nearing  the  western  horizon,  sci- 
ence herself  pointed  to  the  conclusion  that  it  was  about  to  dis- 
appear forever,  together  with  the  great  race  of  ephemera  for 
whom  it  was  created. 

AY  hat    his   hearers   thought   of  this  discourse  I  do  not  re- 
member, but  I  have  heard  that  the  sun  rose  again  the  next 


morning. 


INDEX. 


An  UK,  PROFESSOR,  56. 

Actinism,  71. 

Adams,  Professor,  195. 

Africa,  116. 

Ages,  stellar,  238. 

Air  :  dancing,  17  ;  a  medium,  33 ;  continuous, 
176;  rarefied,  179;  motes,  181;  nimble, 
191.  (See  Atmosphere.') 

Airless  Mountains,  160. 

Air-wave,  185. 

Aitken's  Researches,  181. 

Alaska,  38. 

Aldebaran,  222,  235,  236,  246. 

Algot,  228. 

Allegheny  Observatory,  17,  19,  84,  86.  (See 
Latiglei/.) 

Alphonsus  Ring-plain,  156. 

Alps,  39,  148,  151,  167,  181.  (See  Apen- 
nines, Lunar.) 

American  Astronomers,  227. 

American  Continents,  20,  21,  31.    (See  South.) 

Andalusia,  53. 

Animalcule,  224. 

Animals:  food,  74;  fright,  42.     (See  Log.) 

Antares,  238. 

Ants,  223.     (See  Insects) 

Apennines,  151,  153,  155,  160,  167.  (See 
Alps,  Lunar.) 

Apples,  171. 

Arab  Traditions,  194.     (See  Moslem.) 

Arago,  quoted,  41,  42. 

Archimedes,  94. 

Archimedes  Crater,  151-153,  155. 

Arctic  Cold,  159. 

Arctic  Pole,  96. 

Arcturus,  208,  211. 


Aristillus  Crater,  151. 

Aristotelian  Philosophy,  8. 

Arzachel,  156, 161. 

Asteroids,  128. 

Astrology,  127- 

Astronomers  and  Priests,  1-3.  (Sec  Ameri- 
can, New,  Old.) 

Astronomical  Day,  85,  86. 

Atmosphere,  136,  180 ;  as  a  shield,  216,  220. 
(See  Air.) 

Atolls,  152. 

Auger,  simile,  31. 

Aurora  Borealis,  35,  67,  212. 

Autolycus  Crater,  151. 

Axis,  9,  10. 


BABEL,  96. 

Bain  Telegraph,  88. 

Balloons,  176. 

Bees,  124.     (See  Insects.) 

Berkeley's  Theory,  70. 

Berlin  Observatory,  233. 

Bernieres's  Lens,  103. 

Bessemer  Steel,  104-108. 

Birds,  172,  196,  197.     (See  Animals.) 

Black  Hole,  73. 

Bond,  Professor,  204. 

Boston,  Mass.,  88,  132. 

Bothkamp,  observations  at,  66. 

Breadstuff's,  78,  79.     (See  Grain,  Sun-spots, 

Wheat.) 

Bridges,  20,  68. 

Britain,  Ancient,  1,  234.     (See  England.) 
British  Isles,  14,  25. 
Brocken  Spectre,  55. 


254 


INDEX. 


Brothers,  Mr.,  50. 
Bubbles,  168. 

Buffer,  the  air  as  a,  216,  220. 
Bunseu's  Researches,  12. 
Burnham,  W.  S.,  233. 
Burning-glasses,  102-104. 
Burning  Heat,  160,  163. 


CACTUS,  14,  24. 

Calcutta,  73. 

California,  151,  180. 

Cambric  Needle  (q.  v.),  experiment,  132. 

Cambridge  Observations,  227,  245-247. 

Camera  Obscura,  63. 

Campanus  Crater,  163,  165. 

Candle,  simile,  39. 

Cannon-ball,  5,  38,  41,  98,  135,  186,  211. 

Canopus,  234. 

Carbon,  72,  73,  107,  221. 

Carbonic-acid  Gas,  219. 

Carpenter's  Studio,  140. 

Carrington's  Work,  79,  87- 

Carthage,  116. 

Cassini,  42. 

Cassiopeia,  229. 

Cataclysm,  30. 

Centimetres,  93. 

Chacornac's  Drawing,  33. 

Chambers,  on  sun-spots,  80. 

Charleston  Earthquake  (q.  v.),  42. 

Chemical  Elements,  221,  223. 

Cherry-stone,  comparison,  196. 

Chicago :  great  fire,  134 ;  astronomer,  233. 

China :  lens,  103,  104 ;  soil,  180. 

Chlorophyl,  73. 

Chocolate,  simile,  107. 

Cholera,  80. 

Chromosphere,  7 ;  clouds,  62  ;  forms,  64-68. 

Cinders,  171. 

Clark's  Glasses,  123. 

Cliffs,  164. 

Clock,  135. 

Cloud-ocean,  179. 

Clouds.:  cirrous,  27,  28 ;  beautiful,  54 ;   and 

rain,  111 ;  formed,  249. 
Coal-beds,  115. 
Coal:    energy,  73-75,  111;    destroyed,   97 

wasted,  101 ;  stock,  112. 
Cobweb,  simile,  26. 
Cold  :  and  eclipses,  40  ;  in  planets,  136. 


Colorado,  50. 

Colors :  in  eclipses  (q.  v.),  Go  ;  mental,  70, 
71 ;  in  Jupiter  (q.  r.),  127 ;  in  moon  (q.  4-.), 
168 ;  in  stars  (q.  w.),  227 ;  spectrum  (q.  r.), 
236. 

hornet-hunters,  204,  207. 
omets:  chapter,  199-220;  Donati's,  201, 
204,  205,  207,  209,  217;  one  part,  203; 
parts  and  name,  208;  tail  (q.  v.),  208, 
211;  diameter  and  parts,  216;  spectro- 
scope, elements,  dread,  219 ;  numerous, 
stone,  219,  220  ;  kernel,  220  ;  (1858), 
213-216 ;  (1866),  200. 

Common,  A.  A.,  239,  247. 

Compass,  86. 

Connecticut  Observations,  186,  242. 

Converter,  104-108. 

Coral,  151. 

Corn,  111.     (See  Grain.} 

Corona,  7,  36,  37,  40,  41,  43,  45-52,  55,  56, 
59,  60-62. 

Cotton-mill,  74. 

Counting,  94. 

Cracks,  celestial,  163. 

Craters,  164.     (See  special  names.) 

Crystalline  Structure,  4,  23-27. 

Cyclones,  24,  31,  32,  68. 

DECAY,  248,  249. 

Delambre's  History,  207. 

De  la  Rue's  Engraving,  125. 

Delfthaven,  5. 

Denning's  Theory,  197. 

Diamonds,  melted,  103. 

Dies  Irse,  249. 

Dipper,  207,  208.     (See  Great  Bear,  Polar.) 

Diurnal  Oscillation,  87. 

Dog,  anecdote  of,  42.     (See  Animals.) 

Donati,  201,  204,  205,  207,  209,  213,  217- 

(See  Comets.) 
Double  Stars,  233. 

Draper,  Professor  Henry,  128,  246,  247. 
Ducks,  noise,  188. 
I)u>t,  34,  100,  101,  102,  105,197. 
Dynamite,  182,  185,  220. 

EARTH  :  relations,  3,  4  ;  description  difficult, 
6  ;  temperature  (7.  v.),  34,  101 ;  a  string 
of  earths,  96;  stars  like,  118;  seen  from 
outside,  133-135  ;  craters,  148. 


INDEX. 


255 


Earthquakes,  220.     (See  Charleston.') 
Earth-shine,  107,  172. 

Eclipses :  total,  7,  37 ;  screen,  36 ;  three,  39, 55 ; 
partial,  40;  singular  gloom,  39-43;  caus- 
ing fright,  43  ;  colors  (q.  v.),  48,  56,  61,  65, 
06;  (1842),  41;  (1857),  48;  (1869),  393 
40 ;  (1870),  44,  01  ;  (1871),  50,  66,  68  ; 
(1878),  38,  50,  57,  58.  (See  Total.) 

E-vpt,  110,  234.     (See  Pyramids.') 

Electricity,  13,  75,  76. 

Electric  Light,  7. 

Electric  Spark,  242.     (See  Lightning.') 

Electric  Storm,  84,  85,  88. 

Elizabeth,  Queen,  115. 

Engine-power,  98,  111. 

England  :  fleets,  2  ;  coal,  115.  (See  Britain, 
London.) 

Engraving,  17. 

Enigma,  228. 

Ephemera,  250,  251. 

Equatorial  Landscape,  13,  17,  18,  47. 

Equatorial  Telescope,  122. 

Ericsson :  engravings,  112,  113  ;  discoveries, 
103. 

Eruptive  Promontories,  66-68. 

Etna,  164,  181. 

Europe,  size,  25. 

Evolution,  planetary,  139. 

Explosive  Forces,  182-194. 

Eye,  71,  227. 

Eye-pieces,  47,  63. 


FABRICIUS'S  OBSERVATIONS,  8. 

Fact  and  Fancy,  175. 

Factory,  73. 

Facuhe,  32,  33. 

Falling,  242,  243. 

Falling  Stars,  193.     (See  Meteors,  Shooting.') 

Faraday,  Michael,  76. 

Fault,  technical  term,  156. 

Faust,  139. 

Faye  :  theory,  29-32  ;  on  Cornets'  Tails,  212. 

Fern-like  Forms,  25,  20. 

Filaments,  25-27,  30,  55,  56,  65,  66,  68. 

Fire,  in  sun  (q.  v.),  92.     (See  Flames,  Heat) 

Fixed  Stars,  233. 

Flame-like  Appearances,  23,  24. 

Flames,  65,  66,  69,  185. 

Flashes,  189,  195. 

Flax,  111. 


Flowers,  color  (q.  t\),  70.    (See  Rose,  Plants.) 

Foliage- forms,  32. 

Foutenelle's  Story,  133. 

Forbes's  Observations,  38,  39. 

Frankenstein,  221. 

Franklin's  Discoveries,  76. 

Frauuhofer  Studies,  235. 

French  Institute,  186. 

Frost-crystals  (q.  v.),  23. 

Furnaces,  101. 


GALILEO,  8,  121-123,  139,  140. 
Gas  :  glowing,  44 ;  in  sun,  60. 
Gas-jets,  40,  61,  68,  88. 
Gassendi's  View,  172,  173. 
Gelinck's  Observations,  80. 
Geminids,  196. 
Genii,  193. 

Geographers  and  Geologists,  133. 
Glare,  14,  18,  62-64. 
Glass:  spun,  26;  globe,  145. 
Glow-worms,  7,  117. 
Good  Hope  Observations,  80. 
Gould's  Researches,  80. 
Grain,  prices,  77,  80,  87.     (See  Com,  Sun- 
spots,   Wheat.) 
Gramarye,  92. 
Grass-blades,  66,  72. 
Grasses,  26. 

Gravitation,  72,  203  ;  negative,  215. 
Great  Bear,  207.     (See  Dipper,  Polar.) 
Green's  Maps,  130. 

Greenwich  Observatory,  2, 81, 82, 84, 85, 88, 89. 
Gulliver's  Travels,  131,  132.     (See  Swift.) 
Gunpowder,  186. 
Guns,  135.     (See  Cannon-ball.) 


HALL  ISLAND,  130. 

Hall,  Professor,  131. 

Hand,  illustration,  168. 

Harkness's  Observations,  44. 

Harvests,  90. 

Hastings,  Professor,  60. 

Heat :  development,  13 ;   concentration,  19  ; 

loss,  29 ;  confinement,  33 ;  sensation,   71 ; 

vibrations,  72 ;   energy,   91 ;   amount,   92, 

97  ;  computation,  94-96  ;  diminution,  101 ; 

emission,  102  ;  storage,  111 ;  in  sugar,  188. 

(See  Flames,  Sun.) 


256 


INDEX. 


Hecla,  164,  181. 

Hedgehog-spines,  simile,  68. 

Helmholtz's  Estimates,  98. 

Hengist  and  Horsa,  1.     (See  Britain.} 

Hercules,  238. 

Herschel,  Sir  John:  sun-spots,  12-14;  elec- 
tric storms,  88  ;  comet's  tail,  216. 

Herschel,  Sir  William  :  avoidance  of  light,  18 ; 
prices,  79  ;  sun-spots  (c[.  v.),  129. 

Herschel's  Outlines,  11. 

Holden,  Professor,  124. 

Honeycomb  Structure,  30. 

Huggins's  Experiment,  234,  235. 

Humanity,  deified,  172. 

Human  Race,  250. 

Humboldt,  195. 

Humming-bird,  70. 

Hunt,  Professor,  136,  219. 

Hydrogen,  68,  99,  237. 


IBRAHIM,  KING,  story,  194,  195. 

Ice  :  melted,  95,  96  ;  never  melted,  163, 164. 

Imbriau  Sea,  151. 

Insects,  224,  250.     (See  Ants,  Bees.} 

Iron :  melting,  19,  107 ;  appearance  of  cold, 

25  ;  in  sun,  28 ;  in  man,  221 ;  in  stars,  236, 

237.     (See  Steel.) 
Ironstone,  188. 
Ivy,  115. 


.I\NNSEN'S  OBSERVATIONS,  61. 

Jevons,  Professor,  80. 

Joseph  in  Egypt,  90. 

Jumping,  241,  242. 

Jupiter,  79,  118,  124, 127-129,  156, 185,  229. 


K I:N->IM, TON   MUSEUM,  221. 

Kepler,  on  Comets,  219. 

Kernels,  220. 

Krw,  88. 

KirchofFs  Researches,  12. 

Krakatao,  181, 185,  186. 


LA  HARPE,  quoted,  207. 
Landscape,  169. 

Langley,  Prof.  S.  P. :  drawings,  15,  16,  18, 
19,  21,  22,  25,  28,  30 ;  note-book,  24 ;  ex- 


pedition,   180;    study  of   Reflection,    21f>. 

(See  Allegheny,  Pittx/jury.) 
Latent  Power,  220. 
Laws  of  Nature,  250,  251. 
Leaf-like  Appearances,  23.     (See  Willow.} 
Lenses,  102,  103  ;  Galileo's,  123. 
Leo,  195,  197. 
Liais's  Drawing,  48.  50. 
Lick  Glass,  123. 
Light:  development,  13;  day  and  night,  :>5  ; 

white  {q.  v.},  48 ;  mental  (see  Eye),  71  ; 

from  balloon,  179 ;  transmitted,  227.     (See 

Siat.) 
Lightning,    75,    76,    242,    244,    245.      (See 

Electric.} 

Lilv,  73.     (See  Flowers.) 
Limited  Express  Train,  5. 
Loaf-sugar,  experiment,  188. 
Lockyer's  Land,  130. 
Lockyer's  Solar  Physics,  59,  61,  236,  238. 
Lomhardy,  151. 
London,  111. 
Lost  Pleiad  (q.  v.},  207- 
Louis  XV.,  42. 
Louis  XVI.,  221. 

Lunar  Alps  (q.  v.),  148,  149.     (See  Moon.) 
Lunar  Apennines  (q.  v.),  153. 
Lunar  Shadows,  36,  37,  39,  56 
Lyrids,  196,  200. 


MACARTNEY'S  LENS,  103. 
Maelstrom,  27- 
Magic  Lantern,  simile,  220. 
Magnesium,  236,  237. 
Magnetic  Needle,  81,  82,  84,  85,  87,  89. 
Mammoth  Cave,  40. 

Man,    chemistry    of,    221,    233.      (See    Hu- 
man i/y.) 

Manhattan  Island,  111. 
Mare  Crisium,  143. 
Mare  Serenitatis,  143,  144. 
Mars,  118,  128-132,  148. 
Mason's  Publication,  137. 
Matterhorn,  148,  167. 
Mayflower,  5. 
Meadows,  172. 
Mecca,  175. 
Medusa,  22S. 
Memnon,  234. 
M  creator,  163,  165. 


257 


Mercury,  3,  118,  136,  220. 

Messier,  anecdote,  207. 

Metals,  melted,  103.     (See  Iron.) 

Metaphysics,  70,  71. 

Meteorites  :  around  Saturn,  124  ;  recent,  187  ; 
lawsuit,  187,  188 ;  analyzed,  191,  192 ;  in 
Iowa,  199,  200  ;  swarm,  200 ;  cracking,  211. 

Mrh'ors,  98,  175-198;  (1868),  189.  (See 
Falling,  Shooting.) 

Meunier's  Investigations,  192. 

Mexican  Gulf,  38. 

Microcosm,  222. 

Micromegas,  223. 

Microscope,  224. 

Middle  Ages,  91,  175. 

Milky  Way,  224,  225. 

Milton,  quoted,  14,  38. 

Mind-causation,  70,  71. 

Mirror,  102,  107. 

Mississippi,  134. 

Mites,  224. 

Mizar,  207. 

M'Leod's  Drawing,  44. 

Monochromatic  Light  (^.  v.),  63. 

Montaigne  of  Limoges,  207. 

Mont  Blanc,  156. 

Monte  Rosa,  167. 

Moon :  practical  observations,  2 ;  newly  studied, 
3;  distance,  4-6;  size,  5,  6,  140,  156; 
shadows  (<?.  v),  36,  125  ;  in  sun-eclipse, 
41 ;  planetary  relations,  117-174;  and  Ju- 
piter, 127 ;  *  photograph,  137 ;  full,  141, 
144,  147;  Man  in  the,  143;  mountains, 
144  ;  craters,  147,  148  ;  temperature,  159  ; 
airless,  160 ;  landscape  (q.  v),  169 ;  age, 
171 ;  broken  up,  192 ;  like  comet,  215.  (See 
Lunar.) 

Moslem  Traditions,  175,  194.     (See  Arab.) 

Moss,  160. 

Mouchot's  Engravings,  109,  112. 

Mountain  Sickness,  50,  53. 


NAPLES,  155,  157.     (See  Vesuvius.) 

Napoleon,  80,  134. 

Nasmyth's  Researches,  11, 12, 14,  24,  25, 140. 

Nativity  of  Jesus,  229. 

Nature's  Laws  (q.  v.),  176. 

Nebula,  247. 

Needle,  228.     (See  Cambric.) 

Neptune,  121. 


Nerves,  none  in  camera,  47. 

Nerve  Transmission,  5,  6. 

New  Astronomy,  4,  75,  76,  117,  121,  171, 

193,  222,  224,  227,  235,  246,  248.     (See 

Old.) 

Newcomb,  Professor,  55. 
Newspapers,  printed  by  the  sun,  74. 
Newton,  Professor,  191,  195-197. 
Newton,  Sir  Isaac,  136,  203,  211 ;  on  Comets, 

215,  219. 
Nightmare,  67. 

Northern  Crown,  208,  211,  230. 
Novelists,  theme  for,  193,  228. 
Nucleus,  11,  19,  216.     (See  Comets,  Corona) 


OCEANS,  179. 

Old  Astronomy,  199,  203,  233.     (See  New.) 

Organisms  in  sun  (q.  v),  13. 

Orion,  238,  239,  247. 

Oxygen,  73. 


PACIFIC  OCEAN,  180. 

Palinurus,  243. 

Parable,  224. 

Paris:  Observatory,  42,  233,  247;  Exposi- 
tion, 112. 

Parker's  Lens,  103. 

Peirce,  Professor,  44. 

Pennsylvania  Coal,  97. 

Penumbra,  11,  19,  20. 

Perpignan,  France,  42. 

Perseus,  196. 

Persian  Rugs,  70. 

Philadelphia,  88. 

Philosopher's  Stone,  92. 

Phoebus,  34. 

Phosphorus,  221. 

Photographic  Plate,  71. 

Photography,  9,  19,  128,  236,  237,  241,  244, 
247,  248 ;  rapid,  242. 

Photometer,  56,  108. 

Photometry,  230. 

Photosphere,  7,  17,  64. 

Pickering,  Professor,  132,  227,  228,  246. 

Pico  Summit,  148. 

Piffard,  Dr.  H.  G.,  245. 

Pike's  Peak,  50,  53-57,  60. 

Pilgrim  Fathers,  5. 

Pine-boughs,  25. 


17 


258 


INDEX. 


Pine-trees,  60,  72. 

Pittsburg  Observations,  18,  19.  (See  Alle- 
gheny, Langley. ) 

Planetoids,  196,  197,  229. 

Planets  :  condition,  97  ;  pulverized,  100;  and 
moon,  117-174 ;  isolated,  176.  (See  Ju- 
piter, Mars,  Mercury,  Saturn,  Siriits,  Stars.} 

Plants,  72,  73.     (See  Flowers.) 

Plato  Crater,  147,  148,  151,  152. 

Pleiades,  17,  231,  245.     (See  Lost.) 

Plume,  The,  19,  23,  24,  55. 

Pointers,  208.     (See  Dipper.) 

Poison,  222. 

Polariscope,  49. 

Polarization,  18. 

Polarizing  Eye-piece,  14,  18. 

Polar  Star,  230.     (See  Great  Bear.) 

Polyp,  152. 

Pores,  24. 

Pouillet's  Invention,  93. 

Printing,  indebtedness  to  the  sun,  74. 

Prism,  63,  64.     (See  Colors,  Scarlet.) 

Proctor's  Observations,  14,  59,  69,  87. 

Prospero's  Wand,  221. 

Ptolemy,  155,  161. 

Pyramids,  99,  117,  233,  234.     (See  Egypt.) 

Pyrheliometer,  93. 


RACE,  simile,  179. 

Radiant  Energy,  71,  74 ;  rate,  104. 

Radiation,  101,  108. 

Railway  Explosion,  182,  183. 

Railway,  The,  156. 

Rain,  111. 

Rainbow,  70. 

Ranyard's  Photographs,  50. 

Red  Sea,  116. 

Reflection,  216. 

Repulsive  Force,  215. 

Hibbons,  70,  236. 

Rifts,  163,  164. 

Rings,  123,  124,  152,  155.     (See  Saturn.) 

Rockets,  67,  68. 

Rocky  Mountains,  88,  89,  180. 

Roman  I>oy,  34. 

Rope,  20,  26. 

Rose-leaf,  63,  70.     (See  leaves) 

Rowland's  Photographs,  237. 

Ruskin,  quoted,  29. 

Russia,  134. 


Rutherfurd  Photographs,  8,  9,  137,  143,  155, 
234. 


SAL-AMMONIAC,  14,  25. 

Salisbury  Plain,  1,  2. 

Sandstone,  192. 

Saturn,  118,  119,  121,  123,  124,  127-129, 

136,  215. 

Saturnian  Dwarfs,  223,  224. 
Saul,  comparison,  77. 
Saxon  Forefathers,  1,  2.     (See  Britain.) 
Scarlet,  67.     (See  Colors.) 
Schwabe,  Hofrath,  76,  77,  87. 
Scott,  Sir  Walter,  quoted,  92. 
Screen,  10,  35-37. 
Seas,  lunar  (g.  p.),  143. 
Secchi,  Father,  14,  15,  24,  25,  29,  30,  43,  59, 

235. 

Segmentations,  30,  31. 
Self-luminosity,  215. 
Sextant,  224. 
Shadows,     (See  Lunar.) 
Shakspeare,  quoted,  60,  220. 
Sheaves,  68. 
Shelbyville,  42,  43. 
Sherman,  observations  at,  88. 
Ship,  comparison,  133.     (See  Steamer.) 
Shooting-stars,  35,  193,  196,  198,  199.     (See 

Falling,  Meteors.) 
Sicily,  50.     (See  Etna.) 
Siemens,  Sir  William,  111. 
Sierra  Nevada,  151,  160,  180. 
Signal  Service,  90. 
Silicon,  107. 

Sirius,  179,  222-224,  236-238. 
Slits,  59,  63,  64. 
Smoked  Glass,  11. 
Snow-flakes,  19,  35. 
Snow-like  Forms,  25. 
Sodium,  237. 
Solar  Engine,  75,  109. 
Solar  Light  (q.  v.),  13. 
Solar  Physics,  4, 12,  14.     (See  Sun.) 
Solar  System,  228,  229. 
South  America  {q.  v.),  80. 
South    Carolina,   meteors,    194,   195.      (See 

Charleston.) 
Southern  Cross,  234. 
Space,  181,  211,  224,  227,  229. 
Spain,  expedition,  44. 


INDEX. 


259 


Sparks,  107,  108. 

Spectra,  231,  237- 

Spectres,  54,  55.     (See  Brooke >i) 

Spectroscope,  7,  50,  59,  61,  63,  64,  130,  176, 
198,  219,  222,  233-235,  240. 

Spectrum,  65,  235. 

Spectrum  Analysis,  12. 

Speculations,  193. 

Spinning-wheel,  115. 

Springfield  Observations,  44. 

Spurs,  208,  212,  215. 

Star  of  Bethlehem,  229.     (See  Tycho.) 

Stars :  new  study,  3 ;  location,  4 ;  size,  4, 
230 ;  seen  in  darkness,  35 ;  self-shining 
suns,  35,  118;  host,  117;  variety,  118; 
five,  118 :  elements,  atmosphere,  179 ; 
showers  (see  Meteors),  195  ;  seen  through 
comet,  212,  215  ;  chapter,  221-250 ;  analy- 
sis, children,  222;  distances,  223;  inter- 
vals, 224,  227,  229 ;  colors  (q.  v.),  glory, 
227;  new,  fading,  230;  double,  233;  re- 
lation to  man  (q.  v.),  233;  fixed,  233; 
changing  place,  234  ;  mass,  237 ;  ages,  238  ; 
photographed,  244,  247  ;  chart,  247  ;  death, 
248.  (See  Falling,  Planets,  Shooting.) 

Steam,  74,  75. 

Steamers,  21,  73,  115. 

Steel,  melted,  104-108.     (See  Iron.) 

Stellar  Spectra  (q.  v.),  222,  236,  237,  244,  245. 

Stevenson,  George,  111. 

Stewart's  Observations,  88. 

Stonehenge,  1-3. 

Stones  :  from  heaven,  175, 176, 186, 187, 191, 
193 ;  Iowa,  199,  200.  (See  Meteorites.) 

Stony  hurst  Records,  88. 

Sumbawa  Observations,  181. 

Sunbeams  :  lifting  power,  72 ;  Laputa,  73 ; 
printing,  74;  motes,  215.  (See  Light.) 

Sun :  practical  observations  in  Washington, 
2,  3  ;  new  study,  3  ;  surroundings,  4,  35-69 ; 
distance,  4-6;  size,  5,  6;  a  private,  6; 
views,  6-12,  15,  16,  20 ;  details,  7 ;  fire,  8, 
91,  92  ;  telescopic  view,  8  ;  axis,  9  ;  revo- 
lutions, 10 ;  surface,  17 ;  paper  record,  18  ; 
heat  (q.  v)  and  eye,  19 ;  drawings  exag- 
gerated, 29,  30;  something  brighter,  32; 
atmosphere,  33,  34 ;  slits,  59  ;  miniature, 
64;  flames  (q.  v.),  69;  energy,  70-116 
(see  Heat) ;  versatile  aid,  74 ;  children, 
75,  222  ;  shrinkage,  99  ;  ground  up,  100  ; 
emissive  power,  104;  constitution  and  ap- 


pearance, 111 ;  god,  116 ;  self-shining,  118  ; 
studied  from  mountains,  167  ;  affected  by 
dust  (q.  v.),  185  ;  and  comet,  216  ;  elements, 
233  ;  a  star,  237 ;  life,  238  ;  candle,  249 ; 
anecdote,  250.  (See  Solar.) 

Sunrise,  234. 

Sunset,  181,  182.     (See  Twilight.) 

Suns  :  millions,  224;  dwindling,  227;  periods, 
241. 

Sun-spots,  1-34  passim  ;  ancient,  8 ;  early  ob- 
servations, 8 ;  changing,  9 ;  great,  10,  20, 
24 ;  individuality,  darker,  11 ;  leaves  (<£.  v.), 
11, 12 ;  how  observed,  18, 19 ;  typical,  21, 22 ; 
relative  size,  20  ;  hook-shaped  (see  Plume), 
24 ;  signs  of  chaos,  27 ;  double,  32 ;  weath- 
er, 76,  90  ;  periodicity,  76-78  ;  temperature, 
83 ;  records,  85  ;  variations,  87  ;  (1870),  9, 
15,  16,  20;  (1873),  20-24;  (1875),  25,  28, 
30;  (1876),  30,  32;  (1882),  80, 83-86,  90. 

Superga,  38. 

Swift,  Dean,  73,  131,  132.     (See  Gulliver.) 

Sword  Meteor  (y.  v.),  175. 

TACCHINI'S  INVESTIGATIONS,  43, 49, 62, 66, 68. 

Tail,  215,  216.     (See  Comets.) 

Tan,  71. 

Taylor,  Bayard,  139. 

Telephone,  84,  89. 

Telescopes :  many,  17 ;  best,  134 ;  alone,  227, 

230 ;  use,  233,  234. 
Temperature,  101,   102,  108 ;  of  space,  224, 

227. 

Terminator,  147- 

Thermometer,  71,  93,  102 ;  low,  160,  163. 
Time,  small  divisions,  241. 
Tippoo  Saib,  221. 

Total  Eclipse  (q.  v),  39-48  passim,  55,  59. 
Trees,  lacking,  168. 
Tribune,  The  New  York,  84. 
Trinity  Church,  72. 
Trocadero,  112. 

Trouvelot,  E.  L.,  119,  123,  225. 
Turin,  38. 
Twilight,  small,  38. 
Tycho,  144,  229.     (See  Star.) 
Tyndall,  98. 

UMBRA,  11,  12, 19,  20. 
United  States,  comparison,  24. 
Uranus,  3,  196. 


260 


INDEX. 


VAPOR,  28. 

Vega,  235,  246. 

Vegetables,  74. 

Veils,  14,  17. 

Venus,  118. 

Vernier,  3. 

Vesuvius:  crater,  155, 157;  eruption,  181, 183. 

(See  Naples.) 
Vibrations,  72. 
Victoria,  115. 
Viscous  Fluid,  26. 
Vital  Force,  14. 
Vogel,  H.  C.,  64,  66. 
Voids,  181,  227. 
Volcanoes,  27,  28  ;  in  moon,  167,  193. 


WANDERING  STAR,  101.  (See  Comets,  Falling.) 
Washington:    Observatory,   2,    86-88;    tele- 
scope, 122;  Monument,  182. 
Water,  152;  in  man,  221. 
Waterloo,  80. 
Water-wheel,  111. 
Watson's  Observations,  49. 


Wheat,  prices,  79.     (See  BreadstitjjTs,  Corn, 

Grain,  Sun-spots.) 
Wheel,  comparison,  10. 
Whirlpools,  28,  31. 
Whirlwinds,  23,  31. 
White  Light  (-7.  v.),  48,  62,  63. 
Whitney,  Mount,  177. 
Willow-leaves  (q.  v.),  11,  12,  14. 
Wing,  simile,  215. 
Winlock,  Professor,  44. 
Withered  Surfaces,  168,  171. 
Wood-engraving,  50. 
Worlds  and  Clouds,  249. 
Wrinkles,  172. 


XERES,  Spain  (^.  v.),  44,  53. 


YOUNG,  PROFESSOR  :  spectroscope,  44,  50, 65, 
234  ;  observations,  56,  59,  61,  68,  69  ;  mag- 
netism, 87,  88 ;  radiation,  101. 


ZODIACAL  LIGHT,  55. 


University  Press:  John  Wilson  &  Son,  Cambridge. 


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